Quantum Zeno effect under continuous spin noise measurement in a quantum dot-micropillar cavity

TL;DR

This paper theoretically investigates the quantum Zeno effect in a quantum dot-micropillar cavity system, showing how continuous spin measurement influences spin dynamics and noise correlations, and demonstrating the potential for quantum-limited spin measurement.

Contribution

It provides a microscopic model for spin measurement rate and noise correlations, revealing how continuous detection induces the quantum Zeno effect in a spin-photon interface.

Findings

Quantum Zeno effect slows electron spin precession.

Correlation functions show change in spin noise statistics.

Quantum limit for spin measurement can be achieved with homodyne detection.

Abstract

We theoretically describe the quantum Zeno effect in a spin-photon interface represented by a charged quantum dot in a micropillar cavity. The electron spin in this system entangles with the polarization of the transmitted photons, and their continuous detection leads to the slowing of the electron spin precession in external magnetic field and induces the spin relaxation. We obtain a microscopic expression for the spin measurement rate and calculate the second and fourth order correlation functions of the spin noise, which evidence the change of the spin statistics due to the quantum Zeno effect. We demonstrate, that the quantum limit for the spin measurement can be reached for any probe frequency using the homodyne nondemolition spin measurement, which maximizes the rate of the quantum information gain.