A group of researchers from the United States (MIT), Israel, Croatia and Singapore found that in certain circumstances, transmitted through a sheet of graphene the electrical current may be greater than the phase velocity of propagation of light in the medium, and to produce something like "bang", creating an intense and directed by the photon beam. On reaching informed on pages of the latest edition of Nature Communications. It is argued that this is a new opportunity to convert electricity into light. And it is well controlled process with high efficiency and with a good return.
Graphene is able to capture the light, which is reflected in the appearance of so-called surface plasmons. The plasmons - quasiparticles, or, in other words, the electron response to incident photons. The speed of movement of the plasmons is hundreds of times less than the speed of light in a vacuum and, in fact, reflects the movement of light in graphene environment. The rate of motion of electrons in graphene is extremely high - is 1/300 the speed of light in a vacuum - and can reach and even exceed the speed of movement of the plasmons.
Scientists theoretically proved that at the time of exceeding the speed of the plasmon velocity of the electrons occurs explosive effect similar transition fighter at supersonic speed, only for light. In addressing the "light barrier" is connected to the graphene current source begins to emit photons. It is interesting to note that about 80 years ago, it proved Russian scientists Vavilov and Cherenkov. The discovery of the so-called - the effect of Cerenkov radiation. This glow is caused in the transparent medium of charged particles that move at a speed exceeding the phase velocity of light in this environment.
Controlled illumination of graphene using an electric current opens another opportunity for the development of silicon photonics. For optical channel light travels faster electrons (for infrared optical channel consists of silicon, it is transparent to him). Potentially opening will create a more powerful silicon electronics. It remains only to bring development to the practical implementation. Related Products :
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