Influence of a Random Telegraph Process on the Transport through a Point Contact

TL;DR

This paper models how a classical two-level fluctuator affects transport in point contacts, deriving full counting statistics and noise characteristics for both classical and quantum cases using a transfer matrix approach.

Contribution

It introduces a transfer matrix formalism to compute correlation functions and full counting statistics of point contacts influenced by classical and quantum two-level fluctuators.

Findings

Noise in quantum point contacts includes quantum partitioning and classical fluctuator contributions.

Derived full counting statistics for quantum point contacts with time-dependent transmission.

Extended the model to include multiple two-level fluctuators.

Abstract

We describe the transport properties of a point contact under the influence of a classical two-level fluctuator. We employ a transfer matrix formalism allowing us to calculate arbitrary correlation functions of the stochastic process by mapping them on matrix products. The result is used to obtain the generating function of the full counting statistics of a classical point contact subject to a classical fluctuator, including extensions to a pair of two-level fluctuators as well as to a quantum point contact. We show that the noise in the quantum point contact is a sum of the (quantum) partitioning noise and the (classical) noise due to the two-level fluctuator. As a side result, we obtain the full counting statistics of a quantum point contact with time-dependent transmission probabilities.