Coherence Protection of Electron Spin in Earth-field Range by All-optical Dynamic Decoupling

TL;DR

This paper introduces an all-optical dynamic decoupling method using Raman scattering to suppress decoherence in unshielded atomic electron spins caused by nonlinear Zeeman effects and magnetic field gradients, enhancing precision measurements.

Contribution

The study presents a novel all-optical approach to simultaneously cancel dominant broadening effects in atomic spins, enabling improved coherence in Earth-field range conditions.

Findings

Significant suppression of nonlinear Zeeman effect.

Effective cancellation of magnetic field gradient effects.

Spin control along arbitrary directions achieved.

Abstract

In recent years, unshielded atomic systems have been attracting researchers' attention, in which decoherence is one of the major problems, especially for high precision measurements. The nonlinear Zeeman effect and magnetic field gradient are the main decoherence sources of atomic electron spin in Earth-field range. Here, we propose a method to cancel out the two dominant broadening effects simultaneously by an all-optical dynamic decoupling approach based on Raman scattering in the 87Rb Zeeman sublevels. By adjusting the parameters of the Raman lasers, we realize spin control along an arbitrary direction. We analyze the state evolution of atomic spin under the Raman light control sequence in detail. The results show that both the nonlinear Zeeman effect and magnetic field gradient can be significantly suppressed.