Self-consistent ac quantum transport using nonequilibrium Green functions

Abstract

We develop an approach for self-consistent ac quantum transport in the presence of time-dependent potentials at non-transport terminals. We apply the approach to calculate the high-frequency characteristics of a nanotube transistor with the ac signal applied at the gate terminal. We show that the self-consistent feedback between the ac charge and potential is essential to properly capture the transport properties of the system. In the on-state, this feedback leads to the excitation of plasmons, which appear as pronounced divergent peaks in the dynamic conductance at terahertz frequencies. In the off-state, these collective features vanish, and the conductance exhibits smooth oscillations, a signature of single-particle excitations. The proposed approach is general and will allow the study of the high-frequency characteristics of many other low-dimensional nanoscale materials such as nanowires and graphene-based systems, which are attractive for terahertz devices, including those that exploit plasmonic excitations.

11 pages, 5 figures, accepted in Physical Review B

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Cited by in corpus (10)

• Numerical simulations of time resolved quantum electronics
• Theory of AC quantum transport with fully electrodynamic coupling
• Numerical cookbook for electronic quantum transport at finite frequency
• Full counting statistics for electron transport in periodically driven quantum dots
• Time-dependent quantum transport and power-law decay of the transient current in a nano-relay and nano-oscillator
• High-performance nanoscale topological energy transduction
• Wavepacket representation of leads for efficient simulations of time-dependent electronic transport
• Attenuation and amplification of the transient current in nanojunctions with time-varying gate potentials
• Quantum nonlinear ac transport theory at low frequency
• Dynamics of electron currents in nanojunctions with time-varying components and interactions