ABSTRACT
We propose a new type of optical transistor for a broadband amplification of terahertz radiation. It is made of a graphene-superconductor hybrid, where electrons and Cooper pairs couple by Coulomb forces. The transistor operates via the propagation of surface plasmons in both layers, and the origin of amplification is the quantum capacitance of graphene. It leads to terahertz waves amplification, the negative power absorption, and as a result, the system yields positive gain, and the hybrid acts like an optical transistor, operating with the terahertz light. It can, in principle, amplify even a whole spectrum of chaotic signals (or noise), which is required for numerous biological applications.
ABSTRACT
We report on the novel mechanism of electron scattering in hybrid Bose-Fermi systems consisting of a two-dimensional electron gas in the vicinity of an exciton condensate: We show that in certain ranges of temperatures, the bogolon-pair-mediated scattering proves to be dominating over the conventional acoustic phonon channel, over the single-bogolon scattering, and over the scattering on impurities. We develop a microscopic theory of this effect, focusing on GaAs and MoS_{2} materials, and we find the principal temperature dependence of resistivity, distinct from the conventional phonon-mediated processes. Further, we scrutinize parameters and suggest a way to design composite samples with predefined electron mobilities, and we propose a mechanism of electron pairing for superconductivity.
