Current Noise in ac-Driven Nanoscale Conductors

TL;DR

This paper develops a theoretical framework using non-Hermitian Floquet theory to analyze current fluctuations in ac-driven nanoscale conductors, revealing how tailored ac-fields can suppress noise and control transport properties.

Contribution

It introduces explicit formulas for current and noise spectra in ac-driven nanoscale systems, enabling manipulation of noise levels via ac-field parameters.

Findings

Zero-frequency noise and dc-current can be suppressed by specific ac-fields.

The Fano factor varies with ac-field parameters, showing maxima and minima.

Transport noise can be selectively controlled using ac-sources.

Abstract

The theory for current fluctuations in ac-driven transport through nanoscale systems is put forward. By use of a generalized, non-Hermitian Floquet theory we derive novel explicit expressions for the time-averaged current and the zero-frequency component of the power spectrum of current fluctuations. A distinct suppression of both the zero-frequency noise and the dc-current occurs for suitably tailored ac-fields. The relative level of transport noise, being characterized by a Fano factor, can selectively be manipulated by ac-sources; in particular, it exhibits both characteristic maxima and minima near current suppression.