Quantum Model Of Spin Noise

TL;DR

This paper presents a comprehensive quantum model of spin noise in quantum ensembles, unifying measurement regimes and accounting for arbitrary dynamics, providing a complete description of spin noise and correlations.

Contribution

It introduces a unified open quantum systems framework for spin noise that covers both strong and weak measurements and arbitrary initial states.

Findings

Derived spin noise and correlation functions for various conditions

Unified description applicable to different measurement regimes

Model accommodates arbitrary spin dynamics and initial states

Abstract

Any ensemble of quantum particles exhibits statistical fluctuations known as spin noise. Here, we provide a description of spin noise in the language of open quantum systems. The description unifies the signatures of spin noise under both strong and weak measurements. Further, the model accounts for arbitrary spin dynamics from an arbitrary initial state. In all cases we can find both the spin noise and its time correlation function.