糖心视频

David R. Smith, a physicist formerly at the University of California, San Diego, has been awarded the European Union鈥檚 Descartes Prize for Excellence in Scientific Research for developing at UCSD a new class of composite materials with unusual physical properties that scientists theorized might be possible, but had never before been able to produce in nature.

Smith, now an associate professor at Duke University鈥檚 Pratt School of Engineering, shared with four European researchers the 鈧�1.1 million euro prize 鈥� equivalent to $1.29 million U.S. dollars 鈥� for their contributions to the development of a new class of materials known as 鈥渓eft-handed metamaterials.鈥�

The five scientists, whose achievements created a new sub-discipline of physics, will be presented with the Descartes Prize, named in honor of the French mathematician, scientist and philosopher Rene飥� Descartes, at a ceremony held at the Royal Society in London on December 2.

Selected from a pool of 85 research teams from 22 countries, Smith shares this year's top European Union prize for research with Sir John Pendry of the UK, Eleftherios Economou of Greece, Ekmel Ozbay of Turkey and Costas Soukoulis of Greece. 鈥淚t鈥檚 great to receive this kind of recognition for our work,鈥� Smith said. 鈥淭his group of people has collectively made many significant contributions to really establish this field. It鈥檚 been a real collaborative effort.鈥�

鈥淲e're extremely proud of David for his ground-breaking research on 'left-handed metamaterials' and congratulate him on receiving this prestigious prize,鈥� said M. Brian Maple, chair of UCSD Department of 糖心视频ics. 鈥淲e're especially pleased that the world's first left-handed metamaterials were demonstrated by David and Sheldon Schultz and their co-workers in Professor Schultz's laboratory here at UCSD.鈥�

The unusual property of left-handed metamaterials is its ability to reverse many of the physical properties that govern the behavior of ordinary materials. One such property is the Doppler effect, which makes a train whistle sound higher in pitch as it approaches and lower in pitch as it recedes. According to Maxwell's equations, which describe the relationship between magnetic and electric fields, microwave radiation or light would show the opposite effect in this new class of materials, shifting to lower frequencies as a source approaches and to higher frequencies as it recedes.

Similarly, Maxwell's equations further suggest that lenses that would normally disperse electromagnetic radiation would instead focus it within this composite material. This is because Snell's law, which describes the angle of refraction caused by the change in velocity of light and other waves through lenses, water and other types of ordinary material, is expected to be exactly opposite within this composite.

In 2000, Smith and Sheldon Schultz, a physics professor at UCSD, headed a team of UCSD physicists that demonstrated the first realization of a 鈥渓eft-handed metamaterial,鈥� a composite of copper rings and wires that reverses familiar properties of light. (see: ) The concept underlying the development of that material was patented and licensed by UCSD's Office of Technology Transfer and Intellectual Property Services.

While the material behaves in a manner consistent with the laws of physics, the composite exhibits a reversal of one of the 鈥渞ight-hand rules鈥� of physics which describe a relationship between the electric and magnetic fields and the direction of their wave velocity.

As a result, it is part of a class of materials the UCSD physicists refer to colloquially as 鈥渓eft-handed materials,鈥� after a term coined by Russian theorist V. G. Veselago, who predicted the possibility of such materials in 1968, because they reverse this relationship as well as many of the physical properties that govern the behavior of ordinary materials.

In a paper published in the journal Science the following year, Smith, Schultz and physicist Richard Shelby of UCSD reported the first experimental demonstration that a wedge-shaped metamaterial gives negative refraction. (see: ) The initially controversial finding was later confirmed and named one of the journal Science鈥檚 top ten breakthroughs of the year in 2003.

In natural materials, light always refracts or bends at a positive angle with respect to the angle at which it entered, Smith explained. 鈥淭he novel properties of artificial metamaterials therefore bring a degree of design flexibility that was not possible before,鈥� Smith said.

Many applications for left-handed materials are anticipated. Scientists have already shown how the ability to focus radio waves could lead to smaller and improved magnetic resonance imaging (MRI) machines. (see: ) Metamaterials also have many potential applications for the communications industry, including antennas and waveguides that are much smaller and lighter than those of today.

The Descartes Prize for Excellence in Scientific Research, now in its sixth year, is the most prestigious prize awarded by the European Union in the field of science, recognizing outstanding scientific and technological results achieved through international collaborative research in diverse disciplines. Winners are selected by a grand jury of experts in science, industry and the general public.

Source: University of California, San Diego