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:2007.11307 · Physical Review A

Effect of trap symmetry and atom-atom interactions on a trapped-atom interferometer with internal state labeling

Matthieu Dupont-Nivet, Christoph Ira Westbrook, Sylvain Schwartz

Published Feb 19, 2021• 2 citations
arXivHTMLPDF

Abstract

In this paper, we study the dynamics of a trapped atom interferometer with internal state labeling in the presence of interactions. We consider two situations: an atomic clock in which the internal states remain superposed, and an inertial sensor configuration in which they are separated. From the average spin evolution, we deduce the fringe contrast and the phase shift. In the clock configuration, we recover the well-known identical spin rotation effect (ISRE) which can significantly increase the spin coherence time. We also find that the magnitude of the effect depends on the trap geometry in a way that is consistent with our recent experimental results in a clock configuration [M. Dupont-Nivet, R. Demur, C. I. Westbrook, and S. Schwartz, New J. Phys. 20, 043051 (2018)], where ISRE was not observed. In the case of an inertial sensor, we show that despite the spatial separation it is still possible to increase the coherence time by using mean field interactions to counteract asymmetries of the trapping potential.

DOI
10.1103/physreva.103.023321

Related papers

Contrast and phase-shift of a trapped atom interferometer using a thermal ensemble with internal state labelling

Matthieu Dupont-Nivet, Christoph Ira Westbrook, Sylvain Schwartz

We report a theoretical study of a double-well Ramsey interferometer using internal state labelling. We consider the use of a thermal ensemble of cold atoms rather than a Bose–Einstein condensate to minimise the effects of atomic interactions. To maintain a satisfactory level of coherence in this case, a high degree of symmetry is required between the two arms of the interferometer. Assuming that the splitting and recombination processes are adiabatic, we theoretically derive the phase-shift and the contrast of such an interferometer in the presence of a gravity or an acceleration field. We also consider using a 'shortcut to adiabaticity' protocol to speed up the splitting process and discuss how such a procedure affects the phase shift and contrast. We find that the two procedures lead to phase-shifts of the same form.

arXiv:1606.06008•New Journal of Physics•Nov 6, 2016•26 citations

Experimental study of the role of trap symmetry in an atom-chip interferometer above the Bose–Einstein condensation threshold

Matthieu Dupont-Nivet, Romain Demur, Christoph Ira Westbrook +1 more

We report the experimental study of an atom-chip interferometer using ultracold rubidium 87 atoms above the Bose–Einstein condensation threshold. The observed dependence of the contrast decay time with temperature and with the degree of symmetry of the traps during the interferometer sequence is in good agreement with theoretical predictions published in Dupont-Nivet et al (2016 New J. Phys. 18 113012). These results pave the way for precision measurements with trapped thermal atoms.

arXiv:1801.05361•New Journal of Physics•Apr 9, 2018•11 citations

Interference properties of a trapped atom interferometer in two asymmetric optical dipole traps*

Liyong Wang, Xiao Li, Kunpeng Wang +4 more

We investigate interference properties of a trapped atom interferometer where two symmetric optical dipole traps (ODTs) act as the atomic wave-packets splitter and combiner with internal state labelling. After the preparation of initial superposition states, the atomic wave-packet is adiabatically split and moves into two spatially separate asymmetric ODTs. The atomic wave-packets in two ODTs are then adiabatically recombined after a duration of free evolving in traps, completing the interference cycle of this atom interferometer. We show that the interferogram exhibits a series of periodic revivals in interference visibility. Furthermore, the revival period decreases as the asymmetry of two dipole potentials increases. By introducing an echo sequence to the interferometer, we show that while the echo effect is not influenced by the asymmetry of the two ODTs, the onset of periodic revivals changes by the echo sequence. Our study provides an effective method to cancel or compensate the phase shift caused by position and time correlated force.

Chinese Physics B•Jul 28, 2020•0 citations

Ensemble master equation for a trapped-atom clock with one- and two-body losses

Valentin Ivannikov

An ensemble density matrix model that includes one- and two-body losses is derived for a trapped-atom clock. A trapped-atom clock is mainly affected by one- and two-body losses, generally giving nonexponential decays of populations; nevertheless, three-body recombination is also quantitatively analyzed to demonstrate the boundaries of its practical relevance. The importance of one-body losses is highlighted without which population trapping behavior would be observed. The model is written with decay constants expressed through experimental parameters. It can complement, e.g., the ISRE (identical spin rotation effect) model to improve its predictions: ISRE dramatically increases the ensemble coherence time, hence it enables one to observe the influence of two-body losses on the interferometry contrast envelope. The presented model is useful for Ramsey interferometry and is ready for immediate experimental verification in existing systems.

arXiv:1609.05232•Physical Review A•Feb 14, 2014•2 citations

Coherent population trapping in a Raman atom interferometer

Bing Cheng, Pierre Gillot, Sébastien Merlet +1 more

We investigate the effect of coherent population trapping (CPT) in an atom interferometer gravimeter based on the use of stimulated Raman transitions. We find that CPT leads to significant phase shifts, on the order of a few mrad, which may compromise the accuracy of inertial measurements. We show that this effect is rejected by the $k$-reversal technique, which consists of averaging inertial measurements performed with two opposite orientations of the Raman wave vector $k$, provided that internal states at the input of the interferometer are kept identical for both configurations.

arXiv:1606.02843•Physical Review A•Jun 17, 2016•6 citations

Towards an interferometer with thermal atoms trapped on a chip

Mahdi Ammar, Matthieu Dupont-Nivet, Landry Huet +6 more

Summary form only given. Atom chips [1] have shown to be very successful for trapping and manipulating cold atoms. Atom interferometry in the vicinity of an atom chip has been recently achieved by coherently splitting a Bose-Einstein condensate with radiofrequency [2] and microwave [3] dressing. However, some limitations on the precision of the phase measurement occur in this case due to the phase diffusion process resulting from mean field interactions in the Bose-Einstein condensate.In this communication, we will discuss the possibility of using a thermal (i.e. non-condensed) ensemble of ultra-cold atoms trapped on an atom chip in order to create a trapped-atom interferometer with much weaker atomic interactions. In such a scheme (which can be seen as the atomic equivalent of a white light interferometer in optics), the coherence time will strongly depend on the level of symmetry that can be achieved between the potentials forming the two arms of the interferometer. For example, in a simple model of two harmonic potentials, it can be shown that a slight relative frequency difference Δω/ω can be associated with a limitation on the coherence time T given by the following expression: T≈ 2π1ίω kΘ Δω where Θ is the temperature of the atomic ensemble and k the Boltzmann constant (the latter expression being valid only for kΘ >> ! ω). For example, a relative asymmetry of 10-3 will result, for a temperature of about 1μK, to a limitation on the coherence time of 40ms, which favourably compares to what has been achieved experimentally with Bose-Einstein condensates [2]. We will then discuss how we plan to achieve, with the on-going experiment at Thales TRT [4], a splitting of the atomic cloud with the highest possible level of symmetry. The basic idea is to use internal state labelling on the so-called “clock states” of the 87Rb atom and microwave dressing [3] with two independent coplanar waveguides, each waveguide being preferentially resonant with one of the two internal states involved in the process. This way, we expect to have quasi-independent control over the two arms of the interferometer and thus to be able to achieve a coherent splitting as much symmetrical as possible.We will finally discuss the potential applications of this technique in terms of acceleration and gravity measurement with cold atoms on a chip, which could be of great interest in the future if combined, for example, with high bandwidth microelectromechanical sensors.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•May 1, 2013•1 citation
In this paper, we study the dynamics of a trapped atom interferometer with internal state labeling in the presence of interactions. We consider two situations: an atomic clock in which the internal states remain superposed, and an inertial sensor configuration in which they are separated. From the average spin evolution, we deduce the fringe contrast and the phase shift. In the clock configuration, we recover the well-known identical spin rotation effect (ISRE) which can significantly increase the spin coherence time. We also find that the magnitude of the effect depends on the trap geometry in a way that is consistent with our recent experimental results in a clock configuration [M. Dupont-Nivet, R. Demur, C. I. Westbrook, and S. Schwartz, New J. Phys. 20, 043051 (2018)], where ISRE was not observed. In the case of an inertial sensor, we show that despite the spatial separation it is still possible to increase the coherence time by using mean field interactions to counteract asymmetries of the trapping potential.
We report a theoretical study of a double-well Ramsey interferometer using internal state labelling. We consider the use of a thermal ensemble of cold atoms rather than a Bose–Einstein condensate to minimise the effects of atomic interactions. To maintain a satisfactory level of coherence in this case, a high degree of symmetry is required between the two arms of the interferometer. Assuming that the splitting and recombination processes are adiabatic, we theoretically derive the phase-shift and the contrast of such an interferometer in the presence of a gravity or an acceleration field. We also consider using a 'shortcut to adiabaticity' protocol to speed up the splitting process and discuss how such a procedure affects the phase shift and contrast. We find that the two procedures lead to phase-shifts of the same form.
We investigate interference properties of a trapped atom interferometer where two symmetric optical dipole traps (ODTs) act as the atomic wave-packets splitter and combiner with internal state labelling. After the preparation of initial superposition states, the atomic wave-packet is adiabatically split and moves into two spatially separate asymmetric ODTs. The atomic wave-packets in two ODTs are then adiabatically recombined after a duration of free evolving in traps, completing the interference cycle of this atom interferometer. We show that the interferogram exhibits a series of periodic revivals in interference visibility. Furthermore, the revival period decreases as the asymmetry of two dipole potentials increases. By introducing an echo sequence to the interferometer, we show that while the echo effect is not influenced by the asymmetry of the two ODTs, the onset of periodic revivals changes by the echo sequence. Our study provides an effective method to cancel or compensate the phase shift caused by position and time correlated force.
An ensemble density matrix model that includes one- and two-body losses is derived for a trapped-atom clock. A trapped-atom clock is mainly affected by one- and two-body losses, generally giving nonexponential decays of populations; nevertheless, three-body recombination is also quantitatively analyzed to demonstrate the boundaries of its practical relevance. The importance of one-body losses is highlighted without which population trapping behavior would be observed. The model is written with decay constants expressed through experimental parameters. It can complement, e.g., the ISRE (identical spin rotation effect) model to improve its predictions: ISRE dramatically increases the ensemble coherence time, hence it enables one to observe the influence of two-body losses on the interferometry contrast envelope. The presented model is useful for Ramsey interferometry and is ready for immediate experimental verification in existing systems.
We investigate the effect of coherent population trapping (CPT) in an atom interferometer gravimeter based on the use of stimulated Raman transitions. We find that CPT leads to significant phase shifts, on the order of a few mrad, which may compromise the accuracy of inertial measurements. We show that this effect is rejected by the kkk-reversal technique, which consists of averaging inertial measurements performed with two opposite orientations of the Raman wave vector kkk, provided that internal states at the input of the interferometer are kept identical for both configurations.
Summary form only given. Atom chips [1] have shown to be very successful for trapping and manipulating cold atoms. Atom interferometry in the vicinity of an atom chip has been recently achieved by coherently splitting a Bose-Einstein condensate with radiofrequency [2] and microwave [3] dressing. However, some limitations on the precision of the phase measurement occur in this case due to the phase diffusion process resulting from mean field interactions in the Bose-Einstein condensate.In this communication, we will discuss the possibility of using a thermal (i.e. non-condensed) ensemble of ultra-cold atoms trapped on an atom chip in order to create a trapped-atom interferometer with much weaker atomic interactions. In such a scheme (which can be seen as the atomic equivalent of a white light interferometer in optics), the coherence time will strongly depend on the level of symmetry that can be achieved between the potentials forming the two arms of the interferometer. For example, in a simple model of two harmonic potentials, it can be shown that a slight relative frequency difference Δω/ω can be associated with a limitation on the coherence time T given by the following expression: T≈ 2π1ίω kΘ Δω where Θ is the temperature of the atomic ensemble and k the Boltzmann constant (the latter expression being valid only for kΘ >> ! ω). For example, a relative asymmetry of 10-3 will result, for a temperature of about 1μK, to a limitation on the coherence time of 40ms, which favourably compares to what has been achieved experimentally with Bose-Einstein condensates [2]. We will then discuss how we plan to achieve, with the on-going experiment at Thales TRT [4], a splitting of the atomic cloud with the highest possible level of symmetry. The basic idea is to use internal state labelling on the so-called “clock states” of the 87Rb atom and microwave dressing [3] with two independent coplanar waveguides, each waveguide being preferentially resonant with one of the two internal states involved in the process. This way, we expect to have quasi-independent control over the two arms of the interferometer and thus to be able to achieve a coherent splitting as much symmetrical as possible.We will finally discuss the potential applications of this technique in terms of acceleration and gravity measurement with cold atoms on a chip, which could be of great interest in the future if combined, for example, with high bandwidth microelectromechanical sensors.