Coherent States of Alternating Current,

TL;DR

This paper analyzes the counting statistics of electric current driven by pulses, showing how pulse shape influences fluctuations and introducing a method to calculate these statistics, revealing connections to coherent states and instantons.

Contribution

It develops a comprehensive approach to compute counting statistics for various pulse shapes, highlighting how optimal pulses minimize fluctuations to the dc level.

Findings

Fluctuations depend on pulse shape and can be minimized.

Optimal pulses reduce fluctuations to the dc level.

Statistics relate to the analytic structure of the driving field.

Abstract

We study counting statistics of electric current pumped by pulses of an external field. The fluctuations depend on the pulse shape, and can be minimized by choosing the pulse shape properly. For an optimal pulse shape, the fluctuations are reduced to the {\it dc} level, i.e., they do not depend on the duty cycle of the signal. We develop an approach that allows to calculate all counting statistics for various driving fields, optimal and non-optimal. The statistics depend in an interesting way on the analytic structure of the field time dependence, and display an analogy with coherent states and instantons.