Bose-Einstein Condensate Comagnetometer

Abstract

We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a 87 Rb spinor Bose-Einstein condensate as co-located magnetometers. The hyperfine manifolds feature nearly opposite gyromagnetic ratios and thus the sum of their precession angles is only weakly coupled to external magnetic fields, while being highly sensitive to any effect that rotates both manifolds in the same way. The f = 1 and f = 2 transverse magnetizations and azimuth angles are independently measured by non-destructive Faraday rotation probing, and we demonstrate a 44.0(8) dB common-mode rejection in good agreement with theory. We show how spin-dependent interactions can be used to inhibit 2 → 1 hyperfine relaxing collisions, extending to ∼ 1 s the transverse spin lifetime of the f = 1, 2 mixtures. The technique could be used in high sensitivity searches for new physics on sub-millimeter length scales, precision studies of ultra-cold collision physics, and angle-resolved studies of quantum spin dynamics.

Intrinsic decoherence and recurrences in a large ferromagnetic $F = 1$ spinor Bose-Einstein condensate

“…It is of interest for our purposes that the experiments in ultracold gases showing Bose-Einstein condensation 2 [19][20][21][22] are the closest in dealing with true isolated systems. Yet, these gases, due to atomic collisions, do relax to equilibrium and, when in the presence of external magnetic fields do show decoherence phenomena [23,24]. The study of the magnetization of the latter case is the subject of the present article.…”

Intrinsic Decoherence and Recurrences in a Large Ferromagnetic F = 1 Spinor Bose–Einstein Condensate

“…We shall study here the ferromagnetic case only since the condensate acquires a macroscopic spin texture that makes it behave as a "giant" spin. It is worth mentioning that the system we address is very similar to the recent experimental investigation on the spin dynamics of an F = 1 87 Rb spinor macroscopic condensate, where use of the SBEC as a sensible magnetometer is explored [24]. The present model has also been used to study quantum phase transitions in space [34].…”

“…It is of interest for our purposes that the experiments in ultracold gases showing Bose-Einstein condensation [19][20][21][22] are the closest to dealing with true isolated systems. Yet, these gases, due to atomic collisions, relax to equilibrium and, when in the presence of external magnetic fields, show decoherence phenomena [23,24]. The study of the magnetization of the latter case is the subject of the present article.…”

Sensitive magnetometry in challenging environments

“…Ω is the rotation rate. Comagnetometry vari- ants include utilizing different atomic species [93] and different isotopes [92,94,95] and hyperfine levels of the same atomic species [96,97]. The latter implementation is particularly robust to systematic errors due to magnetic field gradients.…”