We demonstrate a sensitive spatially resolved magnetometer using a spinor Bose-Einstein condensate (BEC) of $^{87}\mathrm{Rb}$ atoms with increased probe fluence. By performing a probe parameter search using a two-polarization phase contrast imaging technique, we find that the probe-induced atom loss, a major constraint in optical magnetometry with high-density gas, can be reduced. We attain a sensitivity of 5.4(6) mrad for the phase measurement of Larmor precession using a measurement area of $1.4\ifmmode\times\else\texttimes\fi{}{10}^{2}\phantom{\rule{3.33333pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{2}$ with a probe fluence of $4.1\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{3.33333pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{\ensuremath{-}2}$. A dc magnetic field sensitivity of $5.0(4)\phantom{\rule{3.33333pt}{0ex}}\mathrm{pT}/\sqrt{\mathrm{Hz}}$ is attained with a probe fluence of $3.9\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{\ensuremath{-}2}$. The results should contribute to further enhancement of the sensitivity of a BEC magnetometer.We demonstrate a sensitive spatially resolved magnetometer using a spinor Bose-Einstein condensate (BEC) of $^{87}\mathrm{Rb}$ atoms with increased probe fluence. By performing a probe parameter search using a two-polarization phase contrast imaging technique, we find that the probe-induced atom loss, a major constraint in optical magnetometry with high-density gas, can be reduced. We attain a sensitivity of 5.4(6) mrad for the phase measurement of Larmor precession using a measurement area of $1.4\ifmmode\times\else\texttimes\fi{}{10}^{2}\phantom{\rule{3.33333pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{2}$ with a probe fluence of $4.1\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{3.33333pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{\ensuremath{-}2}$. A dc magnetic field sensitivity of $5.0(4)\phantom{\rule{3.33333pt}{0ex}}\mathrm{pT}/\sqrt{\mathrm{Hz}}$ is attained with a probe fluence of $3.9\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{\ensuremath{-}2}$. The results should contribute to further enhancement of the sensitivity of a BEC magnetometer.

Physical Review AOct 28, 202112 citations

Many-body Quantum Control of a Spin-1 BEC

Thai M. Hoang, Martin Anquez, Bryce Robbins +4 more

Bulletin of the American Physical SocietyJun 4, 20140 citations

A permanent magnetic film atom chip for Bose–Einstein condensation

B V Hall, S. Whitlock, F Scharnberg +2 more

We present a hybrid atom chip which combines a permanent magnetic film with a micromachined current-carrying structure used to realize a Bose–Einstein condensate (BEC). A novel TbGdFeCo material with large perpendicular magnetization has been tailored to allow small scale, stable magnetic potentials for ultracold atoms. We are able to produce 87 Rb BEC in a magnetic trap based on either the permanent magnetic film or the current-carrying structure. Using the condensate as a magnetic field probe we perform cold atom magnetometry to profile both the field magnitude and gradient as a function of distance from the magnetic film surface. Finally, we discuss future directions for our permanent magnetic film atom chip.We present a hybrid atom chip which combines a permanent magnetic film with a micromachined current-carrying structure used to realize a Bose–Einstein condensate (BEC). A novel TbGdFeCo material with large perpendicular magnetization has been tailored to allow small scale, stable magnetic potentials for ultracold atoms. We are able to produce 87 Rb BEC in a magnetic trap based on either the permanent magnetic film or the current-carrying structure. Using the condensate as a magnetic field probe we perform cold atom magnetometry to profile both the field magnitude and gradient as a function of distance from the magnetic film surface. Finally, we discuss future directions for our permanent magnetic film atom chip.

arXiv:cond-mat/0507435Journal of Physics B Atomic Molecular and Optical PhysicsDec 5, 200533 citations

Sensitive BEC magnetometry with optimized probing

Naota Sekiguchi, Aki Torii, Hiroyuki Toda +4 more

An improved spatial magnetometer using a spinor Bose-Einstein condensate of $^{87}$ Rb atoms is realized utilizing newly developed two-polarization phase contrast imaging. The optical shot noise is suppressed by carefully choosing the probe parameters. We attain a dc-magnetic field sensitivity of 7.7 ${\rm pT/\sqrt{Hz}}$ over a measurement area of 28 ${\rm μm^{2}}$ . The attained sensitivity per unit area is superior to that for other modern low-frequency magnetometers with micrometer-order spatial resolution. This result is a promising step for realizing quantum-enhanced magnetometry surpassing classical methods.An improved spatial magnetometer using a spinor Bose-Einstein condensate of $^{87}$Rb atoms is realized utilizing newly developed two-polarization phase contrast imaging. The optical shot noise is suppressed by carefully choosing the probe parameters. We attain a dc-magnetic field sensitivity of 7.7 ${\rm pT/\sqrt{Hz}}$ over a measurement area of 28 ${\rm μm^{2}}$. The attained sensitivity per unit area is superior to that for other modern low-frequency magnetometers with micrometer-order spatial resolution. This result is a promising step for realizing quantum-enhanced magnetometry surpassing classical methods.

arXiv:2009.07569Sep 16, 20202 citations

We demonstrate a sensitive spatially resolved magnetometer using a spinor Bose-Einstein condensate (BEC) of

^{87}\mathrm{Rb}

atoms with increased probe fluence. By performing a probe parameter search using a two-polarization phase contrast imaging technique, we find that the probe-induced atom loss, a major constraint in optical magnetometry with high-density gas, can be reduced. We attain a sensitivity of 5.4(6) mrad for the phase measurement of Larmor precession using a measurement area of $1.4\ifmmode\times\else\texttimes\fi{}{10}^{2}\phantom{\rule{3.33333pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{2}$ with a probe fluence of $4.1\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{3.33333pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{\ensuremath{-}2}$. A dc magnetic field sensitivity of

5.0(4)\phantom{\rule{3.33333pt}{0ex}}\mathrm{pT}/\sqrt{\mathrm{Hz}}

is attained with a probe fluence of $3.9\ifmmode\times\else\texttimes\fi{}{10}^{5}\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{\ensuremath{-}2}$. The results should contribute to further enhancement of the sensitivity of a BEC magnetometer.

An improved spatial magnetometer using a spinor Bose-Einstein condensate of

^{87}

Rb atoms is realized utilizing newly developed two-polarization phase contrast imaging. The optical shot noise is suppressed by carefully choosing the probe parameters. We attain a dc-magnetic field sensitivity of 7.7

{\rm pT/\sqrt{Hz}}

over a measurement area of 28

{\rm μm^{2}}

. The attained sensitivity per unit area is superior to that for other modern low-frequency magnetometers with micrometer-order spatial resolution. This result is a promising step for realizing quantum-enhanced magnetometry surpassing classical methods.