Eurekalert May 8, 2019
In Weyl semimetals charge carriers behave the way electrons and positrons do in particle accelerators. Researchers in Russia have shown that reactions forbidden for elementary particles can also be forbidden in the crystalline materials known as Weyl semimetals. Specifically, this applies to the forbidden reaction of mutual particle-antiparticle annihilation without light emission. This property suggests that a Weyl semimetal could be the perfect gain medium for lasers. The team gauged the lifetime of an electron-hole pair in a Weyl semimetal to be about 10 nanoseconds which is much longer than in conventional materials used in laser technology. Extending the lifetime of nonequilibrium electrons and holes in novel materials opens prospects for using them in new types of long-wavelength lasers…read more. TECHNICAL ARTICLE
Light emission resulting from a mutual annihilation of electrons and holes is the operating principle of semiconductor lasers. Credit: Elena Khavina/MIPT Press Office