History of metamaterials
Encyclopedia
History of metamaterials shares a common history with artificial dielectrics
in microwave engineering
, as it developed just after World War II
. However, there are seminal explorations of artificial materials for manipulating electromagnetic waves at the end of the 19th century. The history of metamaterials is essentially a history of developing certain types of manufactured materials, which interact at radio frequency
, microwave
and later, optical frequencies
.
Photonic materials have been replacing the electron with the photon of light as the fundamental carrier of information.
The first proof of principle for functioning metamaterials
, and a negative index of refraction occurred in the microwave
range at the beginning of the new millennium. This was followed by the first proof of principle for invisibility cloaking
(shielding an object from view), also in the microwave range - about six years later.
Negative refractive materials have led to the development of metamaterial microwave lenses for miniature wireless system antennas
, which are more efficient than their conventional counterparts. Subwavelength focusing with the superlens
, is also a part of present-day metamaterials research.
united all previous observations, experiments and equations of electricity
, magnetism
into a consistent theory. This is also related to optics. Maxwell's work demonstrated that electricity, magnetism and even light are all manifestations of the same phenomenon, namely the electromagnetic field
.
The concept of using certain constructed materials as a method for manipulating electromagnetic waves dates back to the 19th century. Microwave theory
had developed significantly during the latter part of the 19th century with the cylindrical parabolic reflector
, dielectric lens, microwave absorbers, the cavity radiator, the radiating iris, and the pyramidal electromagnetic horn
. The science involving microwaves also included round square and rectangular waveguides prior to Sir Rayleigh's published results in 1896. Microwave optics, involving the focusing of microwaves, introduced quasi-optical components, and a treatment of microwave optics was published in 1897 (by Righi).
during the 1890's. As officiating professor of physics at Presidency College
he involved himself with laboratory experiments, and studies involving refraction
, diffraction
and polarization, as well as transmitters, receivers and various microwave components.
He connected receiver
s to a sensitive galvanometer
, and developed crystals to be used as a receiver. The crystals operated in the shortwave radio range. Crystals were also developed to detect both white
and ultraviolet light. These crystals were patented in 1904 for their capability to detect electromagnetic radiation
. Furthermore, it appears that his work also anticipated the existence of P-type
and N-type
semiconductors by 60 years.
For the general public in 1895, Bose was able to remotely ring a bell and explode gun powder with the use of electromagnetic waves. In 1896 it was reported that Bose had transmitted electromagnetic signals almost a mile.
In 1897 Bose reported on his microwave research (experiments) at the Royal Institution
in London. There he demonstrated his apparatus at wavelengths that ranged from 2.5 centimeters to 5 millimeters.
experiment on twisted structures. These twisted structures match the geometries that are known as artificial chiral media
in today's terminology. By this time, he had also researched double refraction (birefringence) in crystals. Other research included polarization of "electric waves" that crystals produce. He discovered this type of polarization in other materials including a class of dielectrics.
Karl F. Lindman, from 1914 and into the 1920s, studied artificial chiral media formed by a collection of randomly oriented small spirals. He was written about by present-day researchers in metamaterials, Ismo V. Lindell, Ari H. Sihvola, and Juhani Kurkijarvi.
Chirality as optical activity in a given material is a phenomenon studied since the 19th century. By 1811 a study of quartz
crystals revealed that such crystaline solids rotate the polarization of polarized light denoting optical activity. By 1815 materials other than crystals, such as oil of turpentine were known to exhibit chirality. However the basic cause was not known. Louis Pastuer solved the problem (chirality of the molecules) originating a new discipline known as sterochemistry. At the macroscopic
scale, Lindman applied microwaves to the problem with wire spirals (wire helices) in 1920 and 1922.
s is weighted from the view of antenna beam shaping
within microwave engineering just after World War II. Furthermore, metamaterials appear to be historically linked to the body of research pertaining to artificial dielectrics
throughout the late 1940s, the 1950s and the 1960s. The most common use for artificial dielectrics throughout prior decades has been in the microwave
regime for antenna beam shaping
. The artificial dielectrics had been proposed as a low cost and light weight "tool". Research on artificial dielectrics, other than metamaterials, is still ongoing for pertinent parts of the electromagnetic spectrum.
Artificial dielectrics in microwave engineering have some pioneers: Winston E. Kock
, Seymour Cohn, John Brown, and Walter Rotman
. Periodic artificial structures were proposed by Kock, Rotman, and Sergei Schelkunoff. There is also an extensive reference list that is focused on the properties of artificial dielectrics in the 1990 book, Field theory of guided waves by R. E. Collin.
Schelkunoff achieved notice for contributions to antenna theory and electromagnetic wave propagation.
W. E. Kock proposed metallic and wire lenses for antennas. Some of these are the metallic delay lens, parallel-wire lens, and the wire mesh lens. In addition, he conducted analytical studies regarding the response of customized metallic particles to a quasistatic
electromagnetic radiation. As with the current large group of researchers conveying the behavior of metamaterials, Kock noted behaviors and structure in artificial materials that are similar to metamaterials.
He employed particles, which would be of varying geometric shape
; sphere
s, discs, ellipsoids and prolate
or oblate spheroids, and would be either isolated or set in a repeating pattern as part of an array configuration. Furthermore, he was able to determine that such particles behave as a dielectric
medium. He also noticed that the permittivity
"ε" and permeability
" μ" of these particles can be purposely tuned, but not independently.
With metamaterials, however, local values for both ε and μ are designed as part of the fabrication process, or analytically designed in theoretical studies. Because of this process, individual metamaterial inclusions can be independently tuned.
With artificial dielectrics Kock was able to see that any value for permittivity and permeability, arbitrarily large or small, can be achieved, and that this included the possibility of negative values for these parameters. The optical properties of the medium depended solely on the particles’ geometrical shape and spacing, rather than on their own intrinsic behavior. His work also anticipated the split-ring resonator, a fabricated periodic structure that is a common work horse for metamaterials.
Kock, however, did not investigate simultaneous occurrence of negative values of ε and μ, which has become one of the first achievements defining modern metamaterials. This was because research in artificial materials was oriented toward other goals, such as creating plasma media at RF or microwave frequencies related to the overarching needs of NASA and the space program at that time.
Rotman and R.F. Turner advanced microwave beam shaping systems with a lens that has three perfect focal points; two symmetrically located off-axis and one on-axis. They published the design equations for the improved straight-front-face lens, the evaluation of its phase control capabilities, scanning capabilities, and the demonstrated fabrication techniques applicable to this type of design.
Photonic materials replace electrons with photons of light as the fundamental carriers of information. The photon appears to be a more effiecient carrier of information. Materials that can process photonic signals are in use and in development. Developing photonic materials will lead to further miniaturization of components.
In 1987 Eli Yablonovitch proposed controlling spontaneous emissions and constructing physical zones in periodic dieletrics that forbid certain wavelengths of electromagnetic radiation. These capabilities would be built into three dimenisional periodic dielectric structures (artificial dielectric). He noted that controlling spontaneous emission is desirable for semiconductor processes.
s can be altered through their chemistry
. This has long been known. For example, adding lead
changes the color or hardness of glass
. However, at the end of the 20th century this description expanded.
In the 1990s Sir John Pendry
, a physicist
from Imperial College in London
was consulting for a British company, Marconi Materials Technology, as a condensed matter physics
expert. The company manufactured a stealth technology
- a radiation-absorbing carbon
for naval vessels. However, the company did not understand the physics
of the material. The company asked Pendry if he could figure it out.
Pendry discovered that the radiation absorption
property did not come from the molecular or chemical structure
of the material, i. e., the carbon per se. This property came from the long and thin, physical shape of the carbon fiber
s. He realized rather than conventionally altering a material through its chemistry, as lead does with glass, the behavior of a material can be altered by changing a material’s internal structure on a very fine scale. The very fine scale was less than the wavelength
of electromagnetic radiation
of interest. This could be at microwave
, infrared
, or in limited visible wavelengths.
This new material was viewed as "beyond" conventional materials. Hence, the Greek word "meta" was attached, and these are called metamaterials.
This success led to Pendry proposing to the company that he try to change the magnetic properties
of a non-magnetic material, also by altering its physical structure. The material would not be intrinsically magnetic, nor inherently susceptible to being magnetized. He envisioned fabricating a non-magnetic composite material, which could mimic the spin of charges. This is because the charges that are aligned in spin motion at the atomic level
create a magnetic material. Copper wire is a non-magnetic material.
He envisioned and hypothesized that miniature loops of copper wire, set in a fiberglass
substrate could mimic the spin of electron
s, but on a larger scale. Furthermore, this composite could act like a slab of iron
. In addition, he deduced that a current run through the loops of wire results in a magnetic response.
This metamaterial idea resulted in variations. Cutting the loops results in a magnetic resonator, which acts like a switch. The switch in turn would allow Pendry to determine or alter the magnetic properties of the material simply by choice. At the time, Pendry didn't realize the significance of the two materials he had engineered. By combining the electrical properties of Marconi’s radar-absorbing material with his new man-made magnetic material he had unwittingly placed in his hands a new way to manipulate light
, or electromagnetic radiation. In 1999, Pendry published his new conception of artificially produced magnetic materials in a notable physics journal. This was read by scientists all over the world,, and it "stoked their imagination".
produced an often cited, seminal work on a theoretical material that could produce extraordinary effects that are difficult or impossible to produce in nature. At that time he proposed that a reversal of Snell's law
, an extraordinary lens
, and other exceptional phenomena can occur within the laws of physics. This theory lay dormant for a few decades. There were no materials available in nature, or otherwise, that could physically realize Veselago's analaysis.
Not until thirty-three years later did the properties of this material, a metamaterial
, became a subdiscipline of physics
and engineering
.
However, there were certain observations, demonstrations, and implementations that closely preceded this work. Permittivity
of metals, with values that could be stretched from the positive, to the negative domain, had been studied extensively. In other words, negative permittivity was a known phenomena by the time the first metamaterial was produced. Contemporaries of Kock were involved in this type of research. The concentrated effort was led by the US government for researching interactions between the ionosphere
and the re-entry of NASA space vehicles.
In the 1990s Pendry et al., developed sequentially repeating thin wire structures, analogous to crystal structures. These extended the range of material permittivity. However, a more revolutionary structure developed by Pendry et al., was a structure that could control magnetic interactions (permeability) of the radiated light, albeit only at microwave frequencies. This sequentially repeating, split ring structure, extended material magnetic parameters into the negative. This lattice or periodic, "magnetic" structure was constructed from non-magnetic components.
Hence, in electromagnetic domain, a negative value for permittivity and permeability occurring simultaneously was a requirement to produce the first metamaterials. These were beginning steps for proof of principle regarding Veselago's original 1967 proposal.
In the year 2000 a team of UCSD researchers produced and demonstrated metamaterials, which exhibited unusual physical properties
that were never before produced in nature
. These materials obey the laws of physics, but behave differently from normal materials. In essence these negative index metamaterials were noted for having the ability to reverse many of the physical properties that govern the behavior of ordinary optical materials. One of those unusual properties is the capability to reverse, for the first time, the Snell's law of refraction
. Until this year 2000 demonstration by the UCSD team, the material was unavailable. Advances during the 1990s in fabrication and computation capabilities allowed these first metamaterial
s to be constructed. Thus, testing the "new" metamaterial began for the effects described by Victor Veselago
30 years earlier, but only at first in the microwave frequency
domain. Reversal of group velocity
was explicitly announced in the related published paper. :
Ulf Leonhardt was born in East Germany, and presently occupies the theoretical physics chair at the University of St. Andrews in Scotland
, and is considered one the leaders in the science of creating an invisibility cloak. Around 1999, Leonhardt began work on how to build a cloaking device with a few other colleagues. Leonhardt stated that at the time invisibility was not considered fashionable. He then wrote a theoretical study entitled "Optical Conformal Mapping”. The first sentence sums up the objective: "An invisibility device should guide light around an object as if nothing were there."
In 2005, he sent the paper to three notable scientific journals, Nature
, Nature Physics
, and Science
. Each journal in their turn rejected the paper. In 2006, Physical Review Letters
rejected the paper for publication, as well. However, according to the PRL assessment one of the anonymous reviewers noted that (he or she ) had been to two meetings in the previous months with John Pendry
's group, who were also working on a cloaking device. From the meetings the reviewer also became aware of a patent that Pendry and his colleagues had supposedly filed. Leonhardt, was at the time unaware of Pendry group's work. Because of the Pendry meetings, Leonhardt's work was not really considered new physics by the reviewer and, therefore, did not merit publication in Physical Review Letters.
Later in 2006, Science
(the journal) reversed its decision, and contacted Leonhardt to publish his paper because it had just received a theoretical study from Pendry’s team entitled "Controlling Electromagnetic Fields". Science considered both papers strikingly similar, and published them both in the same issue of Science Express
on May 25, 2006. The published papers touched off research efforts by a dozen groups to build cloaking devices at locations around the globe, which would test out the mathematics of both papers.
Only months after the submission of notable invisibility cloak theories, a practical device was built and demonstrated by David Schurig and David Smith
, engineering researchers, of Duke University
(October 2006). It was limited to the microwave
range, so the object was not invisible to the human eye. However, it demonstrated proof of principle.
Metamaterials scientists
Scopus
- cited by 29. Google Scholar
- cited by 30.
Broad subject category: Physics
.
Description of building a mobile metal plate antenna.
Artificial dielectrics
Artificial dielectrics are artificial electromagnetic materials consisting of arrayed, synthetic substances. The arrays themselves, and the distances between synthetic substances are usually evenly spaced on, or within, a substrate. Hence, the arrays of inclusions are in a periodic or lattice...
in microwave engineering
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
, as it developed just after World War II
History of radar
The history of radar starts with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell's seminal work on electromagnetism...
. However, there are seminal explorations of artificial materials for manipulating electromagnetic waves at the end of the 19th century. The history of metamaterials is essentially a history of developing certain types of manufactured materials, which interact at radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
, microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
and later, optical frequencies
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
.
Photonic materials have been replacing the electron with the photon of light as the fundamental carrier of information.
The first proof of principle for functioning metamaterials
Nims
The Nims is a river in Rhineland-Palatinate, Germany, left tributary of the Prüm. Its total length is 59 km. The Nims originates in the Eifel hills, east of the town Prüm. It flows south through Schönecken, Seffern, and through the western quarters of Bitburg. The Nims joins the Prüm in Irrel....
, and a negative index of refraction occurred in the microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
range at the beginning of the new millennium. This was followed by the first proof of principle for invisibility cloaking
Metamaterial cloaking
Metamaterial cloaking is the scientific application of metamaterials in order to achieve invisibility-cloaking. This is accomplished by manipulating the paths traversed by light through a novel optical material....
(shielding an object from view), also in the microwave range - about six years later.
Negative refractive materials have led to the development of metamaterial microwave lenses for miniature wireless system antennas
Metamaterial antennas
Metamaterial antennas are a class of antennas which use metamaterials to increase performance of miniaturized antenna systems. Their purpose, as with any electromagnetic antenna, is to launch energy into free space...
, which are more efficient than their conventional counterparts. Subwavelength focusing with the superlens
Superlens
A superlens, super lens or perfect lens is a lens which uses metamaterials to go beyond the diffraction limit. The diffraction limit is an inherent limitation in conventional optical devices or lenses. In 2000, a type of lens was proposed, consisting of a metamaterial that compensates for wave...
, is also a part of present-day metamaterials research.
Early electromagnetic media
In the 19th century Maxwell's equationsMaxwell's equations
Maxwell's equations are a set of partial differential equations that, together with the Lorentz force law, form the foundation of classical electrodynamics, classical optics, and electric circuits. These fields in turn underlie modern electrical and communications technologies.Maxwell's equations...
united all previous observations, experiments and equations of electricity
Electric field
In physics, an electric field surrounds electrically charged particles and time-varying magnetic fields. The electric field depicts the force exerted on other electrically charged objects by the electrically charged particle the field is surrounding...
, magnetism
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
into a consistent theory. This is also related to optics. Maxwell's work demonstrated that electricity, magnetism and even light are all manifestations of the same phenomenon, namely the electromagnetic field
Electromagnetic field
An electromagnetic field is a physical field produced by moving electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction...
.
The concept of using certain constructed materials as a method for manipulating electromagnetic waves dates back to the 19th century. Microwave theory
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
had developed significantly during the latter part of the 19th century with the cylindrical parabolic reflector
Parabolic reflector
A parabolic reflector is a reflective device used to collect or project energy such as light, sound, or radio waves. Its shape is that of a circular paraboloid, that is, the surface generated by a parabola revolving around its axis...
, dielectric lens, microwave absorbers, the cavity radiator, the radiating iris, and the pyramidal electromagnetic horn
Horn antenna
A horn antenna or microwave horn is an antenna that consists of a flaring metal waveguide shaped like a horn to direct the radio waves. Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz...
. The science involving microwaves also included round square and rectangular waveguides prior to Sir Rayleigh's published results in 1896. Microwave optics, involving the focusing of microwaves, introduced quasi-optical components, and a treatment of microwave optics was published in 1897 (by Righi).
Jagadish Chandra Bose
Jagadish Chandra Bose was a scientist involved in original microwave researchMicrowave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
during the 1890's. As officiating professor of physics at Presidency College
Presidency College, Kolkata
Presidency University, Kolkata, formerly Hindu College and Presidency College, is a unitary, state aided university, located in Kolkata, West Bengal. and one of the premier institutes of learning of liberal arts and sciences in India. In 2002 it was ranked number one by the weekly news magazine...
he involved himself with laboratory experiments, and studies involving refraction
Refraction
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
, diffraction
Diffraction
Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665...
and polarization, as well as transmitters, receivers and various microwave components.
He connected receiver
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...
s to a sensitive galvanometer
Galvanometer
A galvanometer is a type of ammeter: an instrument for detecting and measuring electric current. It is an analog electromechanical transducer that produces a rotary deflection of some type of pointer in response to electric current flowing through its coil in a magnetic field. .Galvanometers were...
, and developed crystals to be used as a receiver. The crystals operated in the shortwave radio range. Crystals were also developed to detect both white
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
and ultraviolet light. These crystals were patented in 1904 for their capability to detect electromagnetic radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
. Furthermore, it appears that his work also anticipated the existence of P-type
P-type semiconductor
A P-type semiconductor is obtained by carrying out a process of doping: that is, adding a certain type of atoms to the semiconductor in order to increase the number of free charge carriers ....
and N-type
N-type semiconductor
N-type semiconductors are a type of extrinsic semiconductor where the dopant atoms are capable of providing extra conduction electrons to the host material . This creates an excess of negative electron charge carriers....
semiconductors by 60 years.
For the general public in 1895, Bose was able to remotely ring a bell and explode gun powder with the use of electromagnetic waves. In 1896 it was reported that Bose had transmitted electromagnetic signals almost a mile.
In 1897 Bose reported on his microwave research (experiments) at the Royal Institution
Royal Institution
The Royal Institution of Great Britain is an organization devoted to scientific education and research, based in London.-Overview:...
in London. There he demonstrated his apparatus at wavelengths that ranged from 2.5 centimeters to 5 millimeters.
Early chiral media
In 1898, Jagadish Chandra Bose conducted the first microwaveMicrowave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
experiment on twisted structures. These twisted structures match the geometries that are known as artificial chiral media
Chirality (electromagnetism)
The term chiral describes an object, especially a molecule, which has or produces a non-superimposeable mirror image of itself. In chemistry, such a molecule is called an enantiomer or is said to exhibit chirality or enantiomerism...
in today's terminology. By this time, he had also researched double refraction (birefringence) in crystals. Other research included polarization of "electric waves" that crystals produce. He discovered this type of polarization in other materials including a class of dielectrics.
Karl F. Lindman, from 1914 and into the 1920s, studied artificial chiral media formed by a collection of randomly oriented small spirals. He was written about by present-day researchers in metamaterials, Ismo V. Lindell, Ari H. Sihvola, and Juhani Kurkijarvi.
Chirality as optical activity in a given material is a phenomenon studied since the 19th century. By 1811 a study of quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
crystals revealed that such crystaline solids rotate the polarization of polarized light denoting optical activity. By 1815 materials other than crystals, such as oil of turpentine were known to exhibit chirality. However the basic cause was not known. Louis Pastuer solved the problem (chirality of the molecules) originating a new discipline known as sterochemistry. At the macroscopic
Macroscopic
The macroscopic scale is the length scale on which objects or processes are of a size which is measurable and observable by the naked eye.When applied to phenomena and abstract objects, the macroscopic scale describes existence in the world as we perceive it, often in contrast to experiences or...
scale, Lindman applied microwaves to the problem with wire spirals (wire helices) in 1920 and 1922.
20th century artificial dielectrics
Much of the historic research related to metamaterialMetamaterial
Metamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition, using small inhomogeneities to create effective macroscopic behavior....
s is weighted from the view of antenna beam shaping
Radiation pattern
In the field of antenna design the term radiation pattern most commonly refers to the directional dependence of the strength of the radio waves from the antenna or other source ....
within microwave engineering just after World War II. Furthermore, metamaterials appear to be historically linked to the body of research pertaining to artificial dielectrics
Artificial dielectrics
Artificial dielectrics are artificial electromagnetic materials consisting of arrayed, synthetic substances. The arrays themselves, and the distances between synthetic substances are usually evenly spaced on, or within, a substrate. Hence, the arrays of inclusions are in a periodic or lattice...
throughout the late 1940s, the 1950s and the 1960s. The most common use for artificial dielectrics throughout prior decades has been in the microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
regime for antenna beam shaping
Radiation pattern
In the field of antenna design the term radiation pattern most commonly refers to the directional dependence of the strength of the radio waves from the antenna or other source ....
. The artificial dielectrics had been proposed as a low cost and light weight "tool". Research on artificial dielectrics, other than metamaterials, is still ongoing for pertinent parts of the electromagnetic spectrum.
Artificial dielectrics in microwave engineering have some pioneers: Winston E. Kock
Winston E. Kock
Winston Kock was the first Director of NASA Electronics Research Center in Cambridge, Massachusetts from September 1, 1964 to October 1, 1966...
, Seymour Cohn, John Brown, and Walter Rotman
Walter Rotman
Walter Rotman was a Jewish American scientist known for his work in radar and antenna design. Among his inventions were the Rotman lens, the sandwich wire antenna, and the trough waveguide.-Biography:...
. Periodic artificial structures were proposed by Kock, Rotman, and Sergei Schelkunoff. There is also an extensive reference list that is focused on the properties of artificial dielectrics in the 1990 book, Field theory of guided waves by R. E. Collin.
Schelkunoff achieved notice for contributions to antenna theory and electromagnetic wave propagation.
W. E. Kock proposed metallic and wire lenses for antennas. Some of these are the metallic delay lens, parallel-wire lens, and the wire mesh lens. In addition, he conducted analytical studies regarding the response of customized metallic particles to a quasistatic
Quasistatic
Quasistatic can refer to:* Quasistatic process* Quasistatic equilibrium* Quasistatic loading* Quasistatic approximation...
electromagnetic radiation. As with the current large group of researchers conveying the behavior of metamaterials, Kock noted behaviors and structure in artificial materials that are similar to metamaterials.
He employed particles, which would be of varying geometric shape
Geometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
; sphere
Sphere
A sphere is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle in two dimensions, a perfect sphere is completely symmetrical around its center, with all points on the surface lying the same distance r from the center point...
s, discs, ellipsoids and prolate
Prolate spheroid
A prolate spheroid is a spheroid in which the polar axis is greater than the equatorial diameter. Prolate spheroids stand in contrast to oblate spheroids...
or oblate spheroids, and would be either isolated or set in a repeating pattern as part of an array configuration. Furthermore, he was able to determine that such particles behave as a dielectric
Dielectric
A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
medium. He also noticed that the permittivity
Permittivity
In electromagnetism, absolute permittivity is the measure of the resistance that is encountered when forming an electric field in a medium. In other words, permittivity is a measure of how an electric field affects, and is affected by, a dielectric medium. The permittivity of a medium describes how...
"ε" and permeability
Permeability (electromagnetism)
In electromagnetism, permeability is the measure of the ability of a material to support the formation of a magnetic field within itself. In other words, it is the degree of magnetization that a material obtains in response to an applied magnetic field. Magnetic permeability is typically...
" μ" of these particles can be purposely tuned, but not independently.
With metamaterials, however, local values for both ε and μ are designed as part of the fabrication process, or analytically designed in theoretical studies. Because of this process, individual metamaterial inclusions can be independently tuned.
With artificial dielectrics Kock was able to see that any value for permittivity and permeability, arbitrarily large or small, can be achieved, and that this included the possibility of negative values for these parameters. The optical properties of the medium depended solely on the particles’ geometrical shape and spacing, rather than on their own intrinsic behavior. His work also anticipated the split-ring resonator, a fabricated periodic structure that is a common work horse for metamaterials.
Kock, however, did not investigate simultaneous occurrence of negative values of ε and μ, which has become one of the first achievements defining modern metamaterials. This was because research in artificial materials was oriented toward other goals, such as creating plasma media at RF or microwave frequencies related to the overarching needs of NASA and the space program at that time.
Rotman and R.F. Turner advanced microwave beam shaping systems with a lens that has three perfect focal points; two symmetrically located off-axis and one on-axis. They published the design equations for the improved straight-front-face lens, the evaluation of its phase control capabilities, scanning capabilities, and the demonstrated fabrication techniques applicable to this type of design.
Photonic structures
The word 'photonics' appeared in the late 1960s to describe a research field whose goal was to use light to perform functions that traditionally fell within the typical domain of electronics, such as telecommunications, information processing, among other processes. The term photonics more specifically connotes:- The particle properties of light,
- The potential of creating signal processing device technologies using photons,
- The practical application of optics, and
- An analogy to electronicsElectronicsElectronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
.
Photonic materials replace electrons with photons of light as the fundamental carriers of information. The photon appears to be a more effiecient carrier of information. Materials that can process photonic signals are in use and in development. Developing photonic materials will lead to further miniaturization of components.
In 1987 Eli Yablonovitch proposed controlling spontaneous emissions and constructing physical zones in periodic dieletrics that forbid certain wavelengths of electromagnetic radiation. These capabilities would be built into three dimenisional periodic dielectric structures (artificial dielectric). He noted that controlling spontaneous emission is desirable for semiconductor processes.
Invention of the metamaterial
Historically, and conventionally, the function or behavior of materialMaterial
Material is anything made of matter, constituted of one or more substances. Wood, cement, hydrogen, air and water are all examples of materials. Sometimes the term "material" is used more narrowly to refer to substances or components with certain physical properties that are used as inputs to...
s can be altered through their chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
. This has long been known. For example, adding lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
changes the color or hardness of glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
. However, at the end of the 20th century this description expanded.
In the 1990s Sir John Pendry
John Pendry
Sir John Brian Pendry, FRS FInstP is an English theoretical physicist known for his research into refractive indexes and creation of the first practical "Invisibility Cloak"...
, a physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
from Imperial College in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
was consulting for a British company, Marconi Materials Technology, as a condensed matter physics
Condensed matter physics
Condensed matter physics deals with the physical properties of condensed phases of matter. These properties appear when a number of atoms at the supramolecular and macromolecular scale interact strongly and adhere to each other or are otherwise highly concentrated in a system. The most familiar...
expert. The company manufactured a stealth technology
Stealth technology
Stealth technology also termed LO technology is a sub-discipline of military tactics and passive electronic countermeasures, which cover a range of techniques used with personnel, aircraft, ships, submarines, and missiles, to make them less visible to radar, infrared, sonar and other detection...
- a radiation-absorbing carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
for naval vessels. However, the company did not understand the physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
of the material. The company asked Pendry if he could figure it out.
Pendry discovered that the radiation absorption
Physical property
A physical property is any property that is measurable whose value describes a physical system's state. The changes in the physical properties of a system can be used to describe its transformations ....
property did not come from the molecular or chemical structure
Chemical structure
A chemical structure includes molecular geometry, electronic structure and crystal structure of molecules. Molecular geometry refers to the spatial arrangement of atoms in a molecule and the chemical bonds that hold the atoms together. Molecular geometry can range from the very simple, such as...
of the material, i. e., the carbon per se. This property came from the long and thin, physical shape of the carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...
s. He realized rather than conventionally altering a material through its chemistry, as lead does with glass, the behavior of a material can be altered by changing a material’s internal structure on a very fine scale. The very fine scale was less than the wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
of electromagnetic radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
of interest. This could be at microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
, infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
, or in limited visible wavelengths.
This new material was viewed as "beyond" conventional materials. Hence, the Greek word "meta" was attached, and these are called metamaterials.
This success led to Pendry proposing to the company that he try to change the magnetic properties
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.A permanent magnet is an object...
of a non-magnetic material, also by altering its physical structure. The material would not be intrinsically magnetic, nor inherently susceptible to being magnetized. He envisioned fabricating a non-magnetic composite material, which could mimic the spin of charges. This is because the charges that are aligned in spin motion at the atomic level
Atom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...
create a magnetic material. Copper wire is a non-magnetic material.
He envisioned and hypothesized that miniature loops of copper wire, set in a fiberglass
Fiberglass
Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...
substrate could mimic the spin of electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
s, but on a larger scale. Furthermore, this composite could act like a slab of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
. In addition, he deduced that a current run through the loops of wire results in a magnetic response.
This metamaterial idea resulted in variations. Cutting the loops results in a magnetic resonator, which acts like a switch. The switch in turn would allow Pendry to determine or alter the magnetic properties of the material simply by choice. At the time, Pendry didn't realize the significance of the two materials he had engineered. By combining the electrical properties of Marconi’s radar-absorbing material with his new man-made magnetic material he had unwittingly placed in his hands a new way to manipulate light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
, or electromagnetic radiation. In 1999, Pendry published his new conception of artificially produced magnetic materials in a notable physics journal. This was read by scientists all over the world,, and it "stoked their imagination".
Negative refractive index
In 1967, Victor VeselagoVictor Veselago
Victor Georgievich Veselago is a Russian physicist. In 1967, he was the first to publish a theoretical analysis of materials with negative permittivity, ε, and permeability μ....
produced an often cited, seminal work on a theoretical material that could produce extraordinary effects that are difficult or impossible to produce in nature. At that time he proposed that a reversal of Snell's law
Snell's law
In optics and physics, Snell's law is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water and glass...
, an extraordinary lens
Superlens
A superlens, super lens or perfect lens is a lens which uses metamaterials to go beyond the diffraction limit. The diffraction limit is an inherent limitation in conventional optical devices or lenses. In 2000, a type of lens was proposed, consisting of a metamaterial that compensates for wave...
, and other exceptional phenomena can occur within the laws of physics. This theory lay dormant for a few decades. There were no materials available in nature, or otherwise, that could physically realize Veselago's analaysis.
Not until thirty-three years later did the properties of this material, a metamaterial
Metamaterial
Metamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition, using small inhomogeneities to create effective macroscopic behavior....
, became a subdiscipline of physics
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
and engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
.
However, there were certain observations, demonstrations, and implementations that closely preceded this work. Permittivity
Permittivity
In electromagnetism, absolute permittivity is the measure of the resistance that is encountered when forming an electric field in a medium. In other words, permittivity is a measure of how an electric field affects, and is affected by, a dielectric medium. The permittivity of a medium describes how...
of metals, with values that could be stretched from the positive, to the negative domain, had been studied extensively. In other words, negative permittivity was a known phenomena by the time the first metamaterial was produced. Contemporaries of Kock were involved in this type of research. The concentrated effort was led by the US government for researching interactions between the ionosphere
Ionosphere
The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
and the re-entry of NASA space vehicles.
In the 1990s Pendry et al., developed sequentially repeating thin wire structures, analogous to crystal structures. These extended the range of material permittivity. However, a more revolutionary structure developed by Pendry et al., was a structure that could control magnetic interactions (permeability) of the radiated light, albeit only at microwave frequencies. This sequentially repeating, split ring structure, extended material magnetic parameters into the negative. This lattice or periodic, "magnetic" structure was constructed from non-magnetic components.
Hence, in electromagnetic domain, a negative value for permittivity and permeability occurring simultaneously was a requirement to produce the first metamaterials. These were beginning steps for proof of principle regarding Veselago's original 1967 proposal.
In the year 2000 a team of UCSD researchers produced and demonstrated metamaterials, which exhibited unusual physical properties
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
that were never before produced in nature
Nature
Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...
. These materials obey the laws of physics, but behave differently from normal materials. In essence these negative index metamaterials were noted for having the ability to reverse many of the physical properties that govern the behavior of ordinary optical materials. One of those unusual properties is the capability to reverse, for the first time, the Snell's law of refraction
Snell's law
In optics and physics, Snell's law is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water and glass...
. Until this year 2000 demonstration by the UCSD team, the material was unavailable. Advances during the 1990s in fabrication and computation capabilities allowed these first metamaterial
Metamaterial
Metamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition, using small inhomogeneities to create effective macroscopic behavior....
s to be constructed. Thus, testing the "new" metamaterial began for the effects described by Victor Veselago
Victor Veselago
Victor Georgievich Veselago is a Russian physicist. In 1967, he was the first to publish a theoretical analysis of materials with negative permittivity, ε, and permeability μ....
30 years earlier, but only at first in the microwave frequency
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
domain. Reversal of group velocity
Group velocity
The group velocity of a wave is the velocity with which the overall shape of the wave's amplitudes — known as the modulation or envelope of the wave — propagates through space....
was explicitly announced in the related published paper. :
Invisibility cloak
The concept of a cloaking device, or the invisibility cloak, is to steer light waves around an object to make it appear as if nothing were there.Ulf Leonhardt was born in East Germany, and presently occupies the theoretical physics chair at the University of St. Andrews in Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, and is considered one the leaders in the science of creating an invisibility cloak. Around 1999, Leonhardt began work on how to build a cloaking device with a few other colleagues. Leonhardt stated that at the time invisibility was not considered fashionable. He then wrote a theoretical study entitled "Optical Conformal Mapping”. The first sentence sums up the objective: "An invisibility device should guide light around an object as if nothing were there."
In 2005, he sent the paper to three notable scientific journals, Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
, Nature Physics
Nature Physics
Nature Physics, is a monthly, peer reviewed, scientific journal published by the Nature Publishing Group. It was first published in October 2005 . The Chief Editor is Alison Wright, who is a full-time professional editor employed by this journal...
, and Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
. Each journal in their turn rejected the paper. In 2006, Physical Review Letters
Physical Review Letters
Physical Review Letters , established in 1958, is a peer reviewed, scientific journal that is published 52 times per year by the American Physical Society...
rejected the paper for publication, as well. However, according to the PRL assessment one of the anonymous reviewers noted that (he or she ) had been to two meetings in the previous months with John Pendry
John Pendry
Sir John Brian Pendry, FRS FInstP is an English theoretical physicist known for his research into refractive indexes and creation of the first practical "Invisibility Cloak"...
's group, who were also working on a cloaking device. From the meetings the reviewer also became aware of a patent that Pendry and his colleagues had supposedly filed. Leonhardt, was at the time unaware of Pendry group's work. Because of the Pendry meetings, Leonhardt's work was not really considered new physics by the reviewer and, therefore, did not merit publication in Physical Review Letters.
Later in 2006, Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
(the journal) reversed its decision, and contacted Leonhardt to publish his paper because it had just received a theoretical study from Pendry’s team entitled "Controlling Electromagnetic Fields". Science considered both papers strikingly similar, and published them both in the same issue of Science Express
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
on May 25, 2006. The published papers touched off research efforts by a dozen groups to build cloaking devices at locations around the globe, which would test out the mathematics of both papers.
Only months after the submission of notable invisibility cloak theories, a practical device was built and demonstrated by David Schurig and David Smith
David R. Smith
David R. Smith is a renowned American physicist and professor of electrical and computer engineering at Duke University in North Carolina. Smith's research focuses on electromagnetic metamaterials, or materials with a negative index of refraction...
, engineering researchers, of Duke University
Duke University
Duke University is a private research university located in Durham, North Carolina, United States. Founded by Methodists and Quakers in the present day town of Trinity in 1838, the school moved to Durham in 1892. In 1924, tobacco industrialist James B...
(October 2006). It was limited to the microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
range, so the object was not invisible to the human eye. However, it demonstrated proof of principle.
See also
- Split-ring resonator
- Negative index metamaterialsNegative index metamaterialsNegative index metamaterials or negative index materials are artificial structures where the refractive index has a negative value over some frequency range. This does not occur in any known natural materials, and thus is only achievable with engineered structures known as metamaterials...
- SuperlensSuperlensA superlens, super lens or perfect lens is a lens which uses metamaterials to go beyond the diffraction limit. The diffraction limit is an inherent limitation in conventional optical devices or lenses. In 2000, a type of lens was proposed, consisting of a metamaterial that compensates for wave...
- Metamaterial cloakingMetamaterial cloakingMetamaterial cloaking is the scientific application of metamaterials in order to achieve invisibility-cloaking. This is accomplished by manipulating the paths traversed by light through a novel optical material....
- Photonic metamaterialsPhotonic metamaterialsPhotonic metamaterials, also known as Optical metamaterials, are a type of electromagnetic metamaterial, which are designed to interact with optical frequencies which are terahertz , infrared , and eventually, visible wavelengths. As a type of metamaterial, the periodic structures are made up of...
- Metamaterial antennasMetamaterial antennasMetamaterial antennas are a class of antennas which use metamaterials to increase performance of miniaturized antenna systems. Their purpose, as with any electromagnetic antenna, is to launch energy into free space...
- Nonlinear metamaterialsNonlinear metamaterialsA nonlinear metamaterial is an artificially constructed material that can exhibit properties not found in nature. Its response to electromagnetic radiation can be characterized by its permittivity and material permeability. The product of the permittivity and permeability results in the refractive...
- Photonic crystalPhotonic crystalPhotonic crystals are periodic optical nanostructures that are designed to affect the motion of photons in a similar way that periodicity of a semiconductor crystal affects the motion of electrons...
- Seismic metamaterialsSeismic metamaterialsSeismic metamaterials, are metamaterials which are designed to counteract the adverse effects of seismic waves on artificial structures, which exist on or near the surface of the earth...
- Acoustic metamaterialsAcoustic metamaterialsAcoustic metamaterials are artificially fabricated materials designed to control, direct, and manipulate sound in the form of sonic, infrasonic, or ultrasonic waves, as these might occur in gases, liquids, and solids. The hereditary line into acoustic metamaterials follows from theory and research...
- Metamaterial absorberMetamaterial absorberA metamaterial absorber manipulates the loss components of the complex effective parameters, permittivity and magnetic permeability of metamaterials, to create a material with particularly high absorption...
- MetamaterialMetamaterialMetamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition, using small inhomogeneities to create effective macroscopic behavior....
- Plasmonic metamaterialsPlasmonic metamaterialsPlasmonic metamaterials are negative index metamaterials that exploit surface plasmons, which are produced from the interaction of light with metal-dielectric materials. Under specific conditions, the incident light couples with the surface plasmons to create self-sustaining, propagating...
- Terahertz metamaterialsTerahertz metamaterialsTerahertz metamaterials are a new class of composite, artificial materials which interact at terahertz frequencies. The terahertz frequency range used in materials research is usually defined as 0.1 to 10 THz...
- Tunable metamaterialsTunable metamaterialsA tunable metamaterial is a metamaterial with a variable response to an incident electromagnetic wave. This includes remotely controlling how an incident electromagnetic wave interacts with a metamaterial. This means the capablitity to determine whether the EM wave is transmitted, reflected, or...
- Transformation opticsTransformation opticsTransformation optics represents an advancement in the design of optical devices. It is the basis for conceptualizing complex tools in the electromagnetic regime which allows for novel control of light, also known as electromagnetic waves. The mathematics underpinning transformation optics is...
- Theories of cloaking
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- Academic journals
- Metamaterials (journal)Metamaterials (journal)Metamaterials is a peer-reviewed scientific journal that was established in March 2007. It is published by Elsevier in association with the Metamorphose Network of Excellence. The Coordinating Editor is Mikhail Lapine. The journal is published quarterly, with occasional special issues...
- Metamaterials (journal)
- Metamaterials books
- Metamaterials HandbookMetamaterials HandbookMetamaterials Handbook is a two-volume handbook on metamaterials edited by Filippo Capolino .The series is designed to cover all theory and application topics related to electromagnetic metamaterials. Disciplines have combined to study, and develop electromagnetic metamaterials...
- Metamaterials: Physics and Engineering ExplorationsMetamaterials: Physics and Engineering ExplorationsMetamaterials: Physics and Engineering Explorations is a book length introduction to the fundamental research and advancements in electromagnetic composite substances known as electromagnetic metamaterials. The discussion encompasses examination of the physics of metamaterial interactions, the...
- Metamaterials Handbook
- Academic journals
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-
Metamaterials scientists
- John PendryJohn PendrySir John Brian Pendry, FRS FInstP is an English theoretical physicist known for his research into refractive indexes and creation of the first practical "Invisibility Cloak"...
- David R. SmithDavid R. SmithDavid R. Smith is a renowned American physicist and professor of electrical and computer engineering at Duke University in North Carolina. Smith's research focuses on electromagnetic metamaterials, or materials with a negative index of refraction...
- Richard W. ZiolkowskiRichard W. ZiolkowskiRichard W. Ziolkowski is a past president of the IEEE Antennas and Propagation Society , and a former vice president of this same society . In 2006 he was awarded OSA Fellow. He is also an IEEE Fellow....
- Ekmel OzbayEkmel OzbayEkmel Özbay is a Turkish professor of Electrical and Electronics Engineering and Physics Departments at Bilkent University and the director of the Nanotechnology Research Center, and Space Technologies Research Center in Ankara.-Biography:...
- Nader EnghetaNader EnghetaNader Engheta is an Iranian scientist and engineer. He has significantly contributed to novel artificial materials, photonics, nano-structured materials, novel graphene materials, and plasmonics....
- Ulf LeonhardtUlf LeonhardtUlf Leonhardt is a German scientist, born in Schlema, Germany . In 2006, he published the first scientific paper on invisibility cloaking with metamaterials at the same time Pendry's group published their paper in the journal Science...
Further reading and general references
- disseminated by Oxford University Press.Scopus
Scopus
Scopus, officially named SciVerse Scopus, is a bibliographic database containing abstracts and citations for academic journal articles. It covers nearly 18,000 titles from over 5,000 international publishers, including coverage of 16,500 peer-reviewed journals in the scientific, technical, medical,...
- cited by 29. Google Scholar
Google Scholar
Google Scholar is a freely accessible web search engine that indexes the full text of scholarly literature across an array of publishing formats and disciplines. Released in beta in November 2004, the Google Scholar index includes most peer-reviewed online journals of Europe and America's largest...
- cited by 30.
Broad subject category: Physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
.
Description of building a mobile metal plate antenna.
- Invited paper --- Free PDF download.
-- Technical review of metamterials research.