Measurement of finite frequency noise cross-correlations with a resonant circuit

TL;DR

This paper proposes a method to measure finite frequency noise cross-correlations in mesoscopic systems using a resonant LC circuit, enabling direct detection of electron correlations and antibunching effects.

Contribution

It generalizes the resonant circuit setup to directly measure noise cross-correlations via charge fluctuations, including a technique to cancel auto-correlations.

Findings

The method can detect electron-antibunching effects.

It reveals singularities in the spectral density of noise cross-correlations.

The approach is applied to a three-terminal normal metal device.

Abstract

The measurement of finite frequency noise cross-correlations represents an experimental challenge in mesoscopic physics. Here we propose a generalisation of the resonant LC circuit setup of Lesovik and Loosen which allow to probe directly such cross-correlations by measuring the charge fluctuations on the plates of a capacitor. The measuring circuit collects noise contributions at the resonant frequency of the LC circuit. Auto-correlation noise can be canceled out by switching the wires and making two distinct measurements. The measured cross-correlations then depend of four non-symmetrized correlators. This detection method is applied to a normal metal three terminal device. We subsequently discuss to what extent the measurement circuit can detect electron-antibunching and what singularities appear in the spectral density of noise cross-correlations.