Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1707.07600 · Physical Review A

Detection of applied and ambient forces with a matter-wave magnetic gradiometer

Billy Robertson, Andrew R. MacKellar, James Halket, Anna Gribbon, Jonathan D. Pritchard, Aidan S. Arnold, Erling Riis, Paul F. Griffin

Published Nov 16, 2017• 4 citations
arXivHTMLPDF

Abstract

An atom interferometer using a Bose--Einstein condensate of $^{87}\mathrm{Rb}$ atoms is utilized for the measurement of magnetic-field gradients. Composite optical pulses are used to construct a spatially symmetric Mach--Zehnder geometry. By using a biased interferometer we demonstrate the ability to measure small residual forces in our system and discriminate between magnetic and inertial effects. These are a residual ambient magnetic-field gradient of $15\ifmmode\pm\else\textpm\fi{}2$ mG/cm and an inertial acceleration of $0.08\ifmmode\pm\else\textpm\fi{}0.02$ m/${\mathrm{s}}^{2}$. Our method has important applications in the calibration of precision measurement devices and the reduction of systematic errors.

DOI
10.1103/physreva.96.053622

Related papers

Detection of Residual Inertial Forces with A Matterwave Magnetic-Gradiometer

Billy Robertson, Andrew R. MacKellar, James Halket +5 more

An atom interferometer using a Bose-Einstein condensate of $^{87}$Rb atoms is utilized for the measurement of magnetic field gradients. Composite optical pulses are used to construct a spatially symmetric Mach-Zehnder geometry. Using a biased interferometer we demonstrate the ability to measure small residual forces in our system at the position of the atoms. These are a residual magnetic field gradient of 15$\pm$2 mG/cm and and an inertial acceleration of 0.08$\pm$0.02 m/s$^2$. Our method has important applications in the calibration of precision measurement devices and the reduction of systematic errors.

•Jul 24, 2017•0 citations

A BEC Based Precision Gravimeter and Magnetic Gradiometer: Design and Implementation

Kyle S. Hardman

A precision inertial sensor based on the interference of matter waves has been designed and implemented. The apparatus is capable of producing both cold thermal and ultracold Bose-Einstein condensate (BEC) atomic ensembles as the inertial test mass. BECs of up to 5x10^6 Rubidium 87 atoms with an effective temperature of 50nK are produced every 13 seconds using a combination of two and three dimensional magneto-optical traps (2D and 3D MOT) and evaporative cooling in a hybrid magnetic-quadrupole and crossed optical dipole trap. The atomic cloud is then propagated through a vertically oriented Mach-Zehnder interferometer utilizing Bragg diffraction beam splitters. An 2.6m drop tube allows for up to 750ms of free fall and interferometer times of up to 250ms. The drop has four regions of imaging corresponding to 0, 25, 220, 530, and 750ms of expansion. Standard absorption imaging is used for the upper two imaging regions and frequency modulation imaging (FMI) is used for the lower regions. FMI exhibits near atom-shot noise limited signal-to-noise of 948 on a 1x10^6 atom cloud. The inertial reference is provided by the Bragg beam retro-reflector which is suspended via a geometric anti-spring passive vibration isolation system providing 65 dB of isolation at 70 Hz. Prior to the first interferometer pulse the ensemble is placed into a spin superposition of the |F=1> ground state manifold using horizontal co-propagating Raman beams. The three internal spin states remain orthogonal throughout the interferometer sequence resulting in three simultaneous interferometer with separable magnetic gradient and gravitational acceleration signals. The effects of meanfield energy on the interferometric phase uncertainty is explored under current trap conditions. It is found that 30 ms of free expansion prior to the first beam splitter decreases the internal energy such that the expected meanfield phase noise is below 1mrad. No significant decrease in the interferometer contrast is observed for all available T, whereas a thermal test mass interferometer of equivalent longitudinal temperature produces no interference at interferometer times > 100ms. A direct comparison of test mass spatial coherence length in an optically transversely confined interferometer is investigated. The visibility and contrast of a BEC and three thermal sources with varying spatial coherence are compared as a function of interferometer time. At short times, the fringe visibility of a BEC source approaches 100%, nearly independent of p pulse efficiency, while thermal sources have fringe visibilities limited to the p pulse efficiency. More importantly for precision measurement systems, the BEC source maintains interference at interferometer times significantly beyond that of the thermal source. A BEC test mass is used for the simultaneous precision measurement of gravity and magnetic field gradients. An 8 hour data run of a 130ms interferometer shows good agreement between the interferometer output and a theoretical model of the solid earth tides. The residual of the theoretical model and the experimental data show a 1000 run precision of dg/g = 1.45x10^9 corresponding to a phase noise of 3.8mrad. The integrated phase noise of the apparatus shows a sensitivity to magnetic field gradients of 120pT/m. By varying the central spatial position of a 40ms interferometer the magnetic field gradient along a portion of the drop tube is measured.

•Jan 1, 2016•4 citations

Atom-interferometric techniques for measuring uniform magnetic field gradients and gravitational acceleration

B. Barrett, I. Y. Chan, Anantharaman Kumarakrishnan

We discuss techniques for probing the effects of a constant force acting on cold atoms using two configurations of a grating echo-type atom interferometer. Laser-cooled samples of ${}^{85}$Rb with temperatures as low as 2.4 $\ensuremath{\mu}$K have been achieved in a new experimental apparatus with a well-controlled magnetic environment. We demonstrate interferometer signal lifetimes approaching the transit time limit in this system ($\ensuremath{\sim}270$ ms), which is comparable to the time scale achieved by Raman interferometers. Using these long time scales, we experimentally investigate the influence of a homogeneous magnetic field gradient using two- and three-pulse interferometers, which enable us to sense changes in externally applied magnetic field gradients as small as $\ensuremath{\sim}4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ G/cm. We also provide an improved theoretical description of signals generated by both interferometer configurations that accurately models experimental results. With this theory, absolute measurements of $B$ gradients at the level of $3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ G/cm are achieved. Finally, we contrast the suitability of the two- and three-pulse interferometers for precision measurements of the gravitational acceleration, $g$.

arXiv:1104.4577•Physical Review A•Dec 19, 2011•27 citations

A Study of Matter-Wave Diffraction in Bose-Einstein Condensates for Atom Interferometry Applications

Yang Guo

Atom interferometers detect inertial effects with considerably larger sensitivity than that of traditional light wave interferometers. They uti- lize the relative small group velocity of coherent matter waves for more precise measurements, which is crucial for possible next-generation in- ertial navigation systems. In a hybrid optical dipole and magnetic trap system we generate Bose-Einstein condensates to be used as the source of matter waves for atom interferometry. We use tailored light pulse sequences to induce Kapitza-Dirac diffraction in the condensates, splitting them into multiple parts at discrete momentum orders. Nu- merical simulation and experimental realization is given for novel pulse sequences that splits ±4hk momentum orders.

•Jan 1, 2014•0 citations

Simultaneous Precision Gravimetry and Magnetic Gradiometry with a Bose-Einstein Condensate: A High Precision, Quantum Sensor

Kyle S. Hardman, P. J. Everitt, Gordon McDonald +7 more

A Bose-Einstein condensate is used as an atomic source for a high precision sensor. A $5\ifmmode\times\else\texttimes\fi{}1{0}^{6}\text{ }\text{ }\mathrm{atom}$ $F=1$ spinor condensate of $^{87}\mathrm{Rb}$ is released into free fall for up to 750 ms and probed with a $T=130\text{ }\text{ }\mathrm{ms}$ Mach-Zehnder atom interferometer based on Bragg transitions. The Bragg interferometer simultaneously addresses the three magnetic states $|{m}_{f}=1,0,\ensuremath{-}1⟩$, facilitating a simultaneous measurement of the acceleration due to gravity with a 1000 run precision of $\mathrm{\ensuremath{\Delta}}g/g=1.45\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$ and the magnetic field gradient to a precision of $120\text{ }\mathrm{pT}/\mathrm{m}$.

arXiv:1603.01967•Physical Review Letters•Sep 21, 2016•131 citations

Precisely mapping the magnetic field gradient in vacuum with an atom interferometer

Min-Kang Zhou, Zhong-Kun Hu, Xiao‐Chun Duan +3 more

The magnetic field gradient has been measured with an atom interferometer using the magnetic sublevels of $^{87}\mathrm{Rb}$ atoms. The Doppler-insensitive measurement effectively eliminates the contribution from gravity and background vibration noise, and the differential measurement also can reject some systematic errors. A resolution of $300$ pT/mm has been demonstrated with a $90$-s integration time and a spatial resolution of $1.4$ mm. The gradiometer was then used to measure the magnetic field gradient in an ultrahigh-vacuum environment. The technique will also be very useful to subtract the systematic error arising from the magnetic field inhomogeneity in precision atom-interferometry experiments, such as gravity measurement.

Physical Review A•Dec 10, 2010•61 citations
An atom interferometer using a Bose--Einstein condensate of 87Rb^{87}\mathrm{Rb}87Rb atoms is utilized for the measurement of magnetic-field gradients. Composite optical pulses are used to construct a spatially symmetric Mach--Zehnder geometry. By using a biased interferometer we demonstrate the ability to measure small residual forces in our system and discriminate between magnetic and inertial effects. These are a residual ambient magnetic-field gradient of 15\ifmmode±\else\textpm\fi215\ifmmode\pm\else\textpm\fi{}215\ifmmode±\else\textpm\fi2 mG/cm and an inertial acceleration of 0.08\ifmmode±\else\textpm\fi0.020.08\ifmmode\pm\else\textpm\fi{}0.020.08\ifmmode±\else\textpm\fi0.02 m/s2{\mathrm{s}}^{2}s2. Our method has important applications in the calibration of precision measurement devices and the reduction of systematic errors.
An atom interferometer using a Bose-Einstein condensate of 87^{87}87Rb atoms is utilized for the measurement of magnetic field gradients. Composite optical pulses are used to construct a spatially symmetric Mach-Zehnder geometry. Using a biased interferometer we demonstrate the ability to measure small residual forces in our system at the position of the atoms. These are a residual magnetic field gradient of 15$\pm2mG/cmandandaninertialaccelerationof0.082 mG/cm and and an inertial acceleration of 0.082mG/cmandandaninertialaccelerationof0.08\pm0.02m/s0.02 m/s0.02m/s^2$. Our method has important applications in the calibration of precision measurement devices and the reduction of systematic errors.
A precision inertial sensor based on the interference of matter waves has been designed and implemented. The apparatus is capable of producing both cold thermal and ultracold Bose-Einstein condensate (BEC) atomic ensembles as the inertial test mass. BECs of up to 5x10^6 Rubidium 87 atoms with an effective temperature of 50nK are produced every 13 seconds using a combination of two and three dimensional magneto-optical traps (2D and 3D MOT) and evaporative cooling in a hybrid magnetic-quadrupole and crossed optical dipole trap. The atomic cloud is then propagated through a vertically oriented Mach-Zehnder interferometer utilizing Bragg diffraction beam splitters. An 2.6m drop tube allows for up to 750ms of free fall and interferometer times of up to 250ms. The drop has four regions of imaging corresponding to 0, 25, 220, 530, and 750ms of expansion. Standard absorption imaging is used for the upper two imaging regions and frequency modulation imaging (FMI) is used for the lower regions. FMI exhibits near atom-shot noise limited signal-to-noise of 948 on a 1x10^6 atom cloud. The inertial reference is provided by the Bragg beam retro-reflector which is suspended via a geometric anti-spring passive vibration isolation system providing 65 dB of isolation at 70 Hz. Prior to the first interferometer pulse the ensemble is placed into a spin superposition of the |F=1> ground state manifold using horizontal co-propagating Raman beams. The three internal spin states remain orthogonal throughout the interferometer sequence resulting in three simultaneous interferometer with separable magnetic gradient and gravitational acceleration signals. The effects of meanfield energy on the interferometric phase uncertainty is explored under current trap conditions. It is found that 30 ms of free expansion prior to the first beam splitter decreases the internal energy such that the expected meanfield phase noise is below 1mrad. No significant decrease in the interferometer contrast is observed for all available T, whereas a thermal test mass interferometer of equivalent longitudinal temperature produces no interference at interferometer times > 100ms. A direct comparison of test mass spatial coherence length in an optically transversely confined interferometer is investigated. The visibility and contrast of a BEC and three thermal sources with varying spatial coherence are compared as a function of interferometer time. At short times, the fringe visibility of a BEC source approaches 100%, nearly independent of p pulse efficiency, while thermal sources have fringe visibilities limited to the p pulse efficiency. More importantly for precision measurement systems, the BEC source maintains interference at interferometer times significantly beyond that of the thermal source. A BEC test mass is used for the simultaneous precision measurement of gravity and magnetic field gradients. An 8 hour data run of a 130ms interferometer shows good agreement between the interferometer output and a theoretical model of the solid earth tides. The residual of the theoretical model and the experimental data show a 1000 run precision of dg/g = 1.45x10^9 corresponding to a phase noise of 3.8mrad. The integrated phase noise of the apparatus shows a sensitivity to magnetic field gradients of 120pT/m. By varying the central spatial position of a 40ms interferometer the magnetic field gradient along a portion of the drop tube is measured.
We discuss techniques for probing the effects of a constant force acting on cold atoms using two configurations of a grating echo-type atom interferometer. Laser-cooled samples of 85{}^{85}85Rb with temperatures as low as 2.4 $\ensuremath{\mu}$K have been achieved in a new experimental apparatus with a well-controlled magnetic environment. We demonstrate interferometer signal lifetimes approaching the transit time limit in this system ($\ensuremath{\sim}270$ ms), which is comparable to the time scale achieved by Raman interferometers. Using these long time scales, we experimentally investigate the influence of a homogeneous magnetic field gradient using two- and three-pulse interferometers, which enable us to sense changes in externally applied magnetic field gradients as small as $\ensuremath{\sim}4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ G/cm. We also provide an improved theoretical description of signals generated by both interferometer configurations that accurately models experimental results. With this theory, absolute measurements of BBB gradients at the level of $3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ G/cm are achieved. Finally, we contrast the suitability of the two- and three-pulse interferometers for precision measurements of the gravitational acceleration, ggg.
Atom interferometers detect inertial effects with considerably larger sensitivity than that of traditional light wave interferometers. They uti- lize the relative small group velocity of coherent matter waves for more precise measurements, which is crucial for possible next-generation in- ertial navigation systems. In a hybrid optical dipole and magnetic trap system we generate Bose-Einstein condensates to be used as the source of matter waves for atom interferometry. We use tailored light pulse sequences to induce Kapitza-Dirac diffraction in the condensates, splitting them into multiple parts at discrete momentum orders. Nu- merical simulation and experimental realization is given for novel pulse sequences that splits ±4hk momentum orders.
A Bose-Einstein condensate is used as an atomic source for a high precision sensor. A $5\ifmmode\times\else\texttimes\fi{}1{0}^{6}\text{ }\text{ }\mathrm{atom}$ F=1F=1F=1 spinor condensate of 87Rb^{87}\mathrm{Rb}87Rb is released into free fall for up to 750 ms and probed with a T=130  msT=130\text{ }\text{ }\mathrm{ms}T=130  ms Mach-Zehnder atom interferometer based on Bragg transitions. The Bragg interferometer simultaneously addresses the three magnetic states $|{m}_{f}=1,0,\ensuremath{-}1⟩$, facilitating a simultaneous measurement of the acceleration due to gravity with a 1000 run precision of $\mathrm{\ensuremath{\Delta}}g/g=1.45\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$ and the magnetic field gradient to a precision of 120 pT/m120\text{ }\mathrm{pT}/\mathrm{m}120 pT/m.
The magnetic field gradient has been measured with an atom interferometer using the magnetic sublevels of 87Rb^{87}\mathrm{Rb}87Rb atoms. The Doppler-insensitive measurement effectively eliminates the contribution from gravity and background vibration noise, and the differential measurement also can reject some systematic errors. A resolution of 300300300 pT/mm has been demonstrated with a 909090-s integration time and a spatial resolution of 1.41.41.4 mm. The gradiometer was then used to measure the magnetic field gradient in an ultrahigh-vacuum environment. The technique will also be very useful to subtract the systematic error arising from the magnetic field inhomogeneity in precision atom-interferometry experiments, such as gravity measurement.