Synopsis: Superconductor optics

In the domain of unusual optical properties, layered superconductors could be viable materials with a negative index of refraction.
Synopsis figure
V. Golick et al., Phys. Rev. Lett. (2010)

Materials with a negative index of refraction bend and guide a beam of light in unconventional ways—an effect that could be exploited to make perfect lenses. The search for candidate negative-index materials has identified multilayers of high-temperature superconductors as a possibility. Because these materials are anisotropic, the sign of the electrical permittivity (or, more specifically, elements of the permittivity tensor) can change over a certain frequency range, which opens the possibility for negative-index refraction.

Writing in Physical Review Letters, Vladislav Golick and colleagues at Kharkov University in the Ukraine, in collaboration with scientists in the Ukraine, Russia, Japan, and the US, calculate dispersion curves for so-called “surface Josephson-plasma waves” in layered superconductors. They find a branch of these waves above the Josephson plasma frequency, displaying abnormal surface mode behavior. They also identify a window of THz frequencies (above the plasma frequency) where the permittivities switch signs to produce negative-index refraction. At higher frequencies, their model predicts that light incident through a high-index, transparent medium would be completely refracted (no reflection) inside the layered superconductor.

When the superconductor-layer width is below the free path of the surface waves, the refracted waves could be emitted from the edge of the superconductor in the form of a highly collimated beam. With a magnetic field applied parallel to the layers, it should be possible to modulate this channeling effect to make fast switching shutters and mirrors for guiding light. –Saad E. Hebboul


Announcements

More Announcements »

Subject Areas

OpticsSuperconductivity

Previous Synopsis

Biological Physics

Hidden epidemic

Read More »

Next Synopsis

Related Articles

Synopsis: Light Tuner Slows Down to Shift
Optics

Synopsis: Light Tuner Slows Down to Shift

A new design for an optical frequency shifter combines a tunable filter and slow-light techniques. Read More »

Viewpoint: A Tale of Two Domes
Condensed Matter Physics

Viewpoint: A Tale of Two Domes

Iron selenide films peppered with potassium atoms exhibit a high-temperature superconducting phase that emerges separately from a low-temperature superconducting phase. Read More »

Focus: Polariton Laser Upgrade
Optics

Focus: Polariton Laser Upgrade

The emission from a polariton laser shows the coherence that is common to conventional lasers, a step toward using them as high-efficiency alternative light sources. Read More »

More Articles