Dissipative quantum transport in nanoscale transistors

We review our efforts on using numerical simulations to study essential physics of dissipative quantum transport in nanoscale field-effect transistors (FETs). Three types of nanoscale transistors are modeled as examples, (i) graphene nanoribbon (GNR) FETs with a quasi-one-dimensional (1D) channel, (ii) graphene FETs with a two-dimensional channel, and (iii) tunneling FETs with a strained GNR channel. In a quasi-1D channel, inelastic phonon scattering can increase the ballisticity at high drain biases considerably and partly offset the negative effect due to elastic scattering. Interplay between dissipative scattering processes and quantum phenomena, such as Klein tunneling in a graphene FET and band-to-band tunneling in a tunneling FET, play an important role on device characteristics. Coupling between far-from-equilibrium phonons and electrons and transport in the strong electron-phonon coupling regime remain as issues for further study.