Time-Dependent Transport through a Mesoscopic Structure

TL;DR

This paper develops a general theoretical framework for analyzing time-dependent electron transport in mesoscopic structures, revealing phenomena like current ringing and complex nonlinear responses under dynamic voltages.

Contribution

It provides an exact solution for non-interacting cases and explores the effects of temporal phase coherence on current response in mesoscopic systems.

Findings

Observation of current ringing due to phase coherence

Complex time-dependent nonlinear current behavior

Analytical solution for non-interacting electron transport

Abstract

We present a general formulation of the nonlinear, time-dependent current through a small interacting region, where electron energies are changed by time-dependent voltages. An exact solution is obtained for the non-interacting case when the elastic coupling to the leads is independent of energy. Temporal phase coherence in a double-barrier tunneling structure produces ``ringing" in the response of the current to a voltage pulse, which can be observed experimentally in the dc-current by varying the pulse length in a train of voltage pulses. The nonlinear current due to an ac-bias also shows complex time-dependence.