Speeding up the spatial adiabatic passage of matter waves in optical microtraps by optimal control

Negretti, Antonio; Benseny, Albert; Mompart, J.; Calarco, Tommaso

doi:10.1007/s11128-012-0357-z

Cited by 16 publications

(14 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It also diminishes the role of phase fluctuations, ensuring the validity of (1) [8]. Note that the aforementioned condition holds for both time profiles of b(t) used by the inverse engineering method [7] and given in (15) and (16). In Sec.…”

Section: Optimal Control Problem With Constrained Trap Frequencymentioning

confidence: 92%

“…This becomes obvious if one expands b e (s) from (16) in powers of γ − 1. In the limit γ − 1 1, the polynomial profile b p (s) (15) is retrieved. If the extra condition x 2 0 is relaxed, then breather-like (accordion) solutions of (1) are permitted.…”

Section: Comparison With the Inverse Engineering Methods And Discusmentioning

confidence: 99%

“…We finally compare this time with the time obtained from the inverse engineering method under the same assumptions. Note that numerical optimization methods have been used to control a BEC in an optical lattice [13], in a magnetic microtrap [14], and in optical microtraps [15]. Our approach here is different since we use the time-optimal theory of single-input control systems in the plane [16][17][18].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Frictionless decompression in minimum time of Bose-Einstein condensates in the Thomas-Fermi regime

Stefanatos

2012

Phys. Rev. A

View full text Add to dashboard Cite

In this paper we study a fast adiabatic-like expansion of a one-dimensional Bose-Einstein condensate (BEC) in the Thomas-Fermi regime confined in a harmonic potential, using the theory of time-optimal control. We find that under reasonable assumptions suggested by the experimental setup, the minimum-time expansion occurs when the frequency of the potential changes in a bang-bang form between the permitted values. We calculate the necessary expansion time and compare it with that obtained using the state-of-the-art inverse engineering method under the same constraints. We also show that this minimum time scales logarithmically with the expansion factor for large values of the latter. This work is expected to find applications in areas where efficient manipulation of a BEC is of utmost importance, for example, in atom interferometry with a BEC.

show abstract

Section: Optimal Control Problem With Constrained Trap Frequencymentioning

confidence: 92%

Section: Comparison With the Inverse Engineering Methods And Discusmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Frictionless decompression in minimum time of Bose-Einstein condensates in the Thomas-Fermi regime

Stefanatos

2012

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…The suppression of interference can effectively be described in terms of spin dephasing. This decoherence effect can be suppressed by minimizing (for instance, by means of optimal control theory [37,38]) the motional excitations for both spin components. A precise evaluation of the decoherence rate, p , C requires further investigation and it strongly depends on the specific transport details.…”

Section: Decoherence Sourcementioning

confidence: 99%

Decoherence models for discrete-time quantum walks and their application to neutral atom experiments

et al. 2014

View full text Add to dashboard Cite

We discuss decoherence in discrete-time quantum walks in terms of a phenomenological model that distinguishes spin and spatial decoherence. We identify the dominating mechanisms that affect quantum-walk experiments realized with neutral atoms walking in an optical lattice. From the measured spatial distributions, we determine with good precision the amount of decoherence per step, which provides a quantitative indication of the quality of our quantum walks. In particular, we find that spin decoherence is the main mechanism responsible for the loss of coherence in our experiment. We also find that the sole observation of ballistic-instead of diffusive-expansion in position space is not a good indicator of the range of coherent delocalization. We provide further physical insight by distinguishing the effects of short-and long-time spin dephasing mechanisms. We introduce the concept of coherence length in the discrete-time quantum walk, which quantifies the range of spatial coherences. Unexpectedly, we find that quasi-stationary dephasing does not modify the local properties of the quantum walk, but instead affects spatial coherences. For a visual representation of decoherence phenomena in phase space, we have developed a formalism based on a discrete analogue of the Wigner function. We show that the effects of spin and spatial decoherence differ dramatically in momentum space.

show abstract

“…Furthermore, making use of the oscillatory behaviour of equation (2) where n(T ) add = 0 for transport times being multiples of the oscillation period of the atom in the trap ( figure 5), qubit transport on a timescale of single oscillation periods is an evident objective and is subject to active research [38][39][40]. Elaborating this idea leads to advanced nonadiabatic heating-free transport protocols developed in the framework of quantum optimal control [35,[41][42][43] with a potential gain in transport speed of one order of magnitude and the potential to perform thousands of shift operations within the coherence time.…”

Section: Adiabaticity Of Qubit Transportmentioning

confidence: 99%

Fast transport, atom sample splitting and single-atom qubit supply in two-dimensional arrays of optical microtraps

et al. 2012

View full text Add to dashboard Cite

Two-dimensional arrays of optical microtraps created by microoptical elements present a versatile and scalable architecture for neutral atom quantum information processing, quantum simulation and the manipulation of ultra-cold quantum gases. In this paper, we demonstrate the advanced capabilities of this approach by introducing novel techniques and functionalities as well as the combined operation of previous separately implemented functions. We introduce piezo-actuator-based transport of atom ensembles over distances of more than one trap separation, examine the capabilities of rapid atom transport provided by acousto-optical beam steering and analyse the adiabaticity limit for atom transport in these configurations. We implement a spatial light modulator with 8 bit transmission control for the per-site adjustment of the trap depth and the number of atoms loaded. We combine single-site addressing, trap depth control and atom transport in one configuration for demonstrating the splitting of atom ensembles with variable ratio at predefined register sites. Finally, we use controlled sub-poissonian preparation of single trapped atoms from such an ensemble to show that our approach allows for the implementation of a continuous supply of single-atom qubits with high fidelity. These novel

show abstract

Speeding up the spatial adiabatic passage of matter waves in optical microtraps by optimal control

Cited by 16 publications

References 75 publications

Frictionless decompression in minimum time of Bose-Einstein condensates in the Thomas-Fermi regime

Frictionless decompression in minimum time of Bose-Einstein condensates in the Thomas-Fermi regime

Decoherence models for discrete-time quantum walks and their application to neutral atom experiments

Fast transport, atom sample splitting and single-atom qubit supply in two-dimensional arrays of optical microtraps

Contact Info

Product

Resources

About