Spin-squeezed vector atomic magnetometry

TL;DR

This paper introduces a novel cold-atom-based vector magnetometer utilizing spin squeezing, capable of measuring both the magnitude and direction of arbitrary magnetic fields with significantly enhanced sensitivity.

Contribution

It presents a new approach to spin-squeezed atomic magnetometry that works with arbitrary magnetic field directions, improving sensitivity by nearly three orders of magnitude.

Findings

Achieves sensitivity nearly 1000 times better than existing magnetometers.

Can measure both magnitude and direction of magnetic fields.

Compatible with spin squeezing in a practical experimental setup.

Abstract

Atomic magnetometers based on Zeeman shift measurement have the potential for high sensitivity and long-term stability. Like other atomic sensors including atomic clocks and atom interferometers, the atomic magnetometer could in principle be augmented with spin squeezing for further sensitivity enhancement. However, existing atomic magnetometers are not compatible with spin squeezing because the atoms can hardly be in a pure quantum state during operation. A natural challenge is the arbitrary direction of the magnetic field. In this paper, we propose a cold-atom-based magnetometer with spin squeezing that can measure both the magnitude and the direction of an arbitrary magnetic field. For experimentally accessible parameters, we show that the technique described above could achieve a sensitivity nearly three orders of magnitude higher than that of the best existing magnetometers.