Dynamical Scheme for Interferometric Measurements of Full-Counting Statistics

TL;DR

This paper introduces a dynamical interferometric method for measuring the full counting statistics of charge transfer in mesoscopic conductors, enabling extraction from average current measurements and applicable to entanglement entropy analysis.

Contribution

It presents a novel interferometric scheme that allows full counting statistics measurement via average current, controllable counting fields, and robustness against environmental dephasing.

Findings

Full counting statistics obtained from average current measurements.

Method applicable to entanglement entropy in quantum point contacts.

Robustness demonstrated against environmental dephasing.

Abstract

We propose a dynamical scheme for measuring the full counting statistics in a mesoscopic conductor using an electronic Mach-Zehnder interferometer. The conductor couples capacitively to one arm of the interferometer and causes a phase shift which is proportional to the number of transferred charges. Importantly, the full counting statistics can be obtained from average current measurements at the outputs of the interferometer. The counting field can be controlled by varying the time delay between two separate voltage signals applied to the conductor and the interferometer, respectively. As a specific application we consider measuring the entanglement entropy generated by partitioning electrons on a quantum point contact. Our scheme is robust against moderate environmental dephasing and can be realized thanks to recent advances in giga-hertz quantum electronics.