Effect of interparticle interaction in a free-oscillation atomic interferometer

Fogarty, Thomás; Kiely, Anthony; Campbell, Steve; Busch, Thomas

doi:10.1103/physreva.87.043630

Cited by 22 publications

(17 citation statements)

References 32 publications

(51 reference statements)

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“…In addition, we predict that for traps with weak anharmonicity, quantum control methods such as echo and dynamical decoupling can increase the revival amplitude, thereby mitigating the deterioration of the coherence due to the trap anharmonicity and elastic atomic collisions. Raman atomic coherence in a trap is closely related to the field free-oscillation atom interferometry [26,29,[31][32][33][34] and may help to further analyze the limitations and properties of such interferometers. Our results apply also to light storage [12,50,51,53], where the stored atomic coherence is released in the form of light emitted in a controlled direction.…”

Section: Discussionmentioning

confidence: 99%

“…By changing the angle α, the momentum recoilhk eff can be varied between practically zero and 2hk. This allows coupling to the external degrees of freedom of the atoms and the possibility of implementation of spatial multi-mode quantum memory [23,24].Raman atomic coherence in a trap is closely related to the fringe contrast of guided interferometers [25][26][27][28], and more specifically free-oscillation atom interferometers [26,[29][30][31][32][33][34]. These rely on the classical turning points of an underlying harmonic potential for the mirroring of the wave packets.…”

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confidence: 99%

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Revival of Raman coherence of trapped atoms

et al. 2017

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We perform Raman spectroscopy of optically trapped non interacting 87 Rb atoms, and observe revivals of the atomic coherence at integer multiples of the trap period. The effect of coherence control methods such as echo and dynamical decoupling is investigated experimentally, analytically and numerically, along with the effect of the anharmonicity of the trapping potential. The latter is shown to be responsible for incompleteness of the revivals. Coherent Raman control of trapped atoms can be useful in the context of free-oscillation atom intefrerometry and spatial multi-mode quantum memory.Coherent control of cold neutral atomic ensembles can be used for a variety of studies and applications in physics, such as metrology, quantum information, quantum simulators, and fundamental quantum mechanics [1][2][3][4][5][6]. Long coherence times usually imply the need to minimize perturbations on the atoms, as implemented in atomic fountain clocks and atom interferometers. However, in some cases, such as quantum memory [7][8][9][10][11][12][13], there arises also a need for long coherence times in trapped samples. This approach involves challenges such as the inhomogeneous profile of both the external potential and the atomic density [14] and elastic atomic collisions. Coherence has also been shown to revive, in the deep quantum regime, via interaction mechanisms in a Bose-Einstein condensate [15,16].Quantum control of the internal state of a trapped atom can be achieved by the use of microwave (MW) radiation, allowing extremely long coherence times [17][18][19][20][21][22] and enabling the implementation of atom-chip clocks and single-pixel quantum memories.There are, however, applications for which MW control does not suffice. In two-photon stimulated Raman control the momentum recoil is given byhk eff ≈ 2hk sin (α/2), whereh is the reduced Planck constant, k is the wave number of the Raman beams and α is the angle between them. By changing the angle α, the momentum recoilhk eff can be varied between practically zero and 2hk. This allows coupling to the external degrees of freedom of the atoms and the possibility of implementation of spatial multi-mode quantum memory [23,24].Raman atomic coherence in a trap is closely related to the fringe contrast of guided interferometers [25][26][27][28], and more specifically free-oscillation atom interferometers [26,[29][30][31][32][33][34]. These rely on the classical turning points of an underlying harmonic potential for the mirroring of the wave packets. A thermal atom free-oscillation Raman interferometer allows for Ramsey π/2 → π/2 interferometry which is completely impossible to perform in freespace, utilizing the periodicity of the trapping potential. This type of interferometer is sensitive to time-dependent * Current address: Kirchhoff-

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Revival of Raman coherence of trapped atoms

et al. 2017

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“…Many-particle quantum descriptions of solitons can be found in Refs. [30][31][32][33][34][35][36][37][38][39][40][41]. * christoph.weiss@durham.ac.uk Beyond enabling us to predict parameters of superballistic spreading of the center-of-mass density, the analytical solution presented in the present paper of our numerical model [10] also allows us to quantitatively predict the timescale on which the transition from short-time diffusive to long-time ballistic behavior observed numerically in Ref.…”

Section: Introductionmentioning

confidence: 98%

Superballistic center-of-mass motion in one-dimensional attractive Bose gases: Decoherence-induced Gaussian random walks in velocity space

et al. 2016

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We show that the spreading of the center-of-mass density of ultracold attractively interacting bosons can become superballistic in the presence of decoherence, via single-, two-and/or three-body losses. In the limit of weak decoherence, we analytically solve the numerical model introduced in [Phys. Rev. A 91, 063616 (2015)]. The analytical predictions allow us to identify experimentally accessible parameter regimes for which we predict superballistic spreading of the center-of-mass density. Ultracold attractive Bose gases form weakly bound molecules; quantum matter-wave bright solitons. Our computer-simulations combine ideas from classical field methods ("truncated Wigner") and piecewise deterministic stochastic processes. While the truncated Wigner approach to use an average over classical paths as a substitute for a quantum superposition is often an uncontrolled approximation, here it predicts the exact root-mean-square width when modeling an expanding Gaussian wave packet. In the superballistic regime, the leading-order of the spreading of the center-of-mass density can thus be modeled as a quantum superposition of classical Gaussian random walks in velocity space.

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“…For interferometric setups, inserting 'obstacles' in the interferometric pathways [24] can be used both for splitting and recombining [25] the atomic beam or solitons [26], similar to light impinging on a half-silvered mirror. Another possibility of building interferometers is the freeoscillation atom interferometer, where the ground-state wave function in a harmonic trap is excited by a laser pulse into a left and right moving part, which collides again after half an oscillation period similar to a Michelson interferometer [27][28][29][30][31][32]. When the trapped condensate is initially spatially displaced and impacted by a * vbolsing@physnet.uni-hamburg.de † pschmelc@physnet.uni-hamburg.de centered impurity dissipative transport [33], dipole oscillations [34] as well as effects of the inter-particle interactions can been studied [32].…”

Section: Introductionmentioning

confidence: 99%

“…Another possibility of building interferometers is the freeoscillation atom interferometer, where the ground-state wave function in a harmonic trap is excited by a laser pulse into a left and right moving part, which collides again after half an oscillation period similar to a Michelson interferometer [27][28][29][30][31][32]. When the trapped condensate is initially spatially displaced and impacted by a * vbolsing@physnet.uni-hamburg.de † pschmelc@physnet.uni-hamburg.de centered impurity dissipative transport [33], dipole oscillations [34] as well as effects of the inter-particle interactions can been studied [32]. In both interferometric setups above, a coherent splitting and recombination is important in order to increase the contrast of the interference fringes.…”

Section: Introductionmentioning

confidence: 99%

Ultracold bosonic scattering dynamics off a repulsive barrier: Coherence loss at the dimensional crossover

2017

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We explore the impact of dimensionality on the scattering of a small bosonic ensemble in an elongated harmonic trap off a centered repulsive barrier, thereby taking particle correlations into account. The loss of coherence as well as the oscillation of the center of mass are studied and we analyze the influence of both particle and spatial correlations. Two different mechanisms of coherence losses in dependence of the aspect ratio are found. For small aspect ratios, loss of coherence between the region close to the barrier and outer regions occurs, due to spatial correlations, and for large aspect ratios, incoherence between the two density fragments of the left and right side of the barrier arises, due to particle correlations. Apart form the decay of the center of mass motion induced by the reflection and transmission, further effects due to the particle and spatial correlations are explored. For tight transversal traps, the amplitude of the center of mass oscillation experiences a weaker damping, which can be traced back to the population of a second natural orbital, and for a weaker transversal confinement, we detect a strong decay, due to the possibility of transferring energy to transversal excited modes. These effects are enhanced if the aspect ratio is integer valued.

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Effect of interparticle interaction in a free-oscillation atomic interferometer

Cited by 22 publications

References 32 publications

Revival of Raman coherence of trapped atoms

Revival of Raman coherence of trapped atoms

Superballistic center-of-mass motion in one-dimensional attractive Bose gases: Decoherence-induced Gaussian random walks in velocity space

Ultracold bosonic scattering dynamics off a repulsive barrier: Coherence loss at the dimensional crossover

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