Quantum Zeno effect and quantum nondemolition spin measurement in a quantum dot–micropillar cavity in the strong coupling regime

Abstract

We theoretically describe the quantum Zeno effect in a spin-photon interface represented by a charged quantum dot in a micropillar cavity in the strong coupling regime. This simplest model allows for various generalizations for the different systems. We derive a simple expression for the spin measurement rate, which allows one to tune the electron spin precession frequency in an external magnetic field and spin relaxation time. We calculate the spin noise bispectrum, which reveals the qualitative change of the spin dynamics with an increase of the measurement strength and proves the quantum nature of the spin noise. We also calculate the quantum information gain rate and find the conditions when it equals the spin dephasing rate, i.e., reaches the quantum limit.