Modelling the effect of charge noise on the exchange interaction between spins

TL;DR

This paper models how charge noise, represented as random telegraph noise, affects the exchange interaction between spins, providing analytic tools to predict decoherence in spin-based quantum systems.

Contribution

It introduces a novel analytic framework for calculating the impact of charge noise on spin exchange interactions, including multiple fluctuators and spectral distributions.

Findings

Derived explicit superoperator expressions for spin pairs under charge noise.

Extended the model to include multiple fluctuators and spectral distributions.

Provided a method to incorporate noise effects into quantum spin system analyses.

Abstract

We describe how the effect of charge noise on a pair of spins coupled via the exchange interaction can be calculated by modelling charge fluctuations as a random telegraph noise process using probability density functions. We develop analytic expressions for the time dependent superoperator of a pair of spins as a function of fluctuation amplitude and rate. We show that the theory can be extended to include multiple fluctuators, in particular, spectral distributions of fluctuators. These superoperators can be included in time dependent analyses of the state of spin systems designed for spintronics or quantum information processing to determine the decohering effects of exchange fluctuations.