Bilayer pseudoSpin field effect transistor (BiSFET): A proposed logic device and circuits

The authors have recently proposed a new type of gated bilayer graphene-based transistor based on many-body tunneling, for ultra-low power (perhaps 1000 X compared to CMOS) room temperature operation. The physics of this system can be addressed by treating the layer (top and bottom) degree of freedom as a pseudospin, much like spin (up and down) in a ferromagnet. Electrons in one layer of a bilayer system can pair with holes in the opposite layer resulting in electron-hole-pairs/excitons (bosons) which then can condense and induce coherence between the layers, effectively shorting them through a many-body tunneling current at low interlayer bias, even when the singleparticle tunneling current is small. This Bose condensate current has been observed experimentally only in GaAs/AlGaAs bilayer systems at very low-temperatures and under high magnetic fields. It has been predicted recently, however, that this condensate could occur possibly above room temperature absent magnetic fields in an ntype and p-type graphene layer pair due to a unique synergy of graphene properties: carrier confinement to a single atomic layer, symmetric electron-hole band structures, very low density of states, and no bandgap.