Suppression of Spin-Exchange Relaxation Using Pulsed Parametric Resonance

TL;DR

This paper presents a method to suppress spin-exchange relaxation in alkali-metal atoms using pulsed parametric resonance, significantly improving magnetometer performance at Earth's magnetic field levels.

Contribution

The authors introduce a pulsed resonance technique that effectively eliminates spin-exchange dephasing, enhancing magnetic field measurement sensitivity.

Findings

Spin-exchange relaxation is reduced by the pulse duty cycle.

Resonant transverse pumping is achieved at 0.1 Gauss.

Magnetometer response is significantly enhanced.

Abstract

We demonstrate that spin-exchange dephasing of Larmor precession at near-earth-scale fields is effectively eliminated by dressing the alkali-metal atom spins in a sequence of AC-coupled 2-pi pulses, repeated at the Larmor precession frequency. The contribution of spin-exchange collisions to the spectroscopic line width is reduced by a factor of the duty cycle of the pulses. We experimentally demonstrate resonant transverse pumping in magnetic fields as high as 0.1 Gauss, present experimental measurements of the suppressed spin-exchange relaxation, and show enhanced magnetometer response relative to a light-narrowed scalar magnetometer.