Shot noise control in ac-driven nanoscale conductors

TL;DR

This paper develops a formalism to analyze current and shot noise in ac-driven nanoscale conductors, revealing how electromagnetic fields can coherently suppress current and noise, applicable across various driving regimes.

Contribution

It introduces a non-Hermitian Floquet formalism to derive explicit expressions for current and shot noise in ac-driven nanoscale conductors, extending beyond traditional approximations.

Findings

Derived explicit formulas for current and shot noise.

Identified regimes where noise suppression occurs.

Connected formalism with existing approximation methods.

Abstract

We derive within a time-dependent scattering formalism expressions for both the current through ac-driven nanoscale conductors and its fluctuations. The results for the time-dependent current, its time average, and, above all, the driven shot noise properties assume an explicit and serviceable form by relating the propagator to a non-Hermitian Floquet theory. The driven noise cannot be expressed in terms of transmission probabilities. The results are valid for a driving of arbitrary strength and frequency. The connection with commonly known approximation schemes such as the Tien-Gordon approach or a high-frequency approximation is elucidated together with a discussion of the corresponding validity regimes. Within this formalism, we study the coherent suppression of current and noise caused by properly chosen electromagnetic fields.