We investigate laser-cooled atoms periodically driven by pulsed standing waves of light tuned close to an open atomic transition. This nonunitary system displays survival resonances for certain driving frequencies. The survival resonances emerge as a result of the matter-wave Talbot-Lau effect, similar to the Talbot effect causing quantum resonances in the atom optics δ-kicked rotor. Since the Talbot-Lau effect occurs for incoherent waves, the survival resonances can be observed using thermal atoms. A microlensing effect can enhance the height and incisiveness of the resonances. This may find applications in precision measurements.

Quantum engineering using photonic structures offer new capabilities for atom-photon interactions for quantum optics and atomic physics, which could eventually lead to integrated quantum devices. Despite the rapid progress in the variety of structures, coherent excitation of the motional states of atoms in a photonic waveguide using guided modes has yet to be demonstrated. Here, we use the waveguide mode of a hollow-core photonic crystal fibre to manipulate the mechanical Fock states of single atoms in a harmonic potential inside the fibre. We create a large array of Schrödinger cat states, a quintessential feature of quantum physics and a key element in quantum information processing and metrology, of approximately 15000 atoms along the fibre by entangling the electronic state with the coherent harmonic oscillator state of each individual atom. Our results provide a useful step for quantum information and simulation with a wide range of photonic waveguide systems.

In order to obtain the all-round molecular properties of the AlH2 system and the corresponding dynamical characteristics of Al+H2(v=0, j=0)→H+AlH reaction, three significant global adiabatic potential energy surfaces of free...

We do a proof-of-principle demonstration of an atomic gravimeter based on survival resonances of dissipatively driven atoms. Exposing laser-cooled atoms to a sequence of near-resonant standing-wave light pulses reveals survival resonances when the standing-wave interference pattern accelerates. The resonant accelerations determine the local gravitational acceleration and we achieve a precision of 5 ppm with a drop distance less than 1 mm. The incisiveness of the resonances scales with the square of the drop time. Present results indicate that an appropriately designed atomic gravimeter based on survival resonances might be able to reach a precision of 1 μGal with a 10-cm-high fountain. The relatively simple experimental construction of this technique may be of interest for a compact absolute atomic gravimeter.

. (2017) 'Resonant transfer of large momenta from nite-duration pulse sequences. ', Physical review A., 95 (3). 033601 .Further information on publisher's website:https://doi.org/10.1103/PhysRevA.95.033601Publisher's copyright statement:Reprinted with permission from the American Physical Society: Physical Review A 95, 033601 c (2017) by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modied, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. We experimentally investigate the atom optics kicked particle at quantum resonance using finite duration kicks. Even though the underlying process is quantum interference, it can be well described by an -pseudoclassical model. The -pseudoclassical model agrees well with our experiments for a wide range of parameters. We investigate the parameters yielding maximal momentum transfer to the atoms and find that this occurs in the regime where neither the short pulse approximation nor the Bragg condition is valid. Nonetheless, the momentum transferred to the atoms can be predicted using a simple scaling law, which provides a powerful tool for choosing optimal experimental parameters. We demonstrate this in a measurement of the Talbot time (from which h/M can be deduced), in which we coherently split atomic wave functions into superpositions of momentum states that differ by 200 photon recoils. Our work may provide a convenient way to implement large momentum difference beam splitters in atom interferometers.

Cold atoms trapped and guided in hollow-core photonic crystal fibers provide a scalable diffraction-free setting for atom–light interactions for quantum technologies. However, due to the mismatch of the depth and spatial extension of the trapping potential from free space to the fiber, the number of cold atoms in the fiber is mainly determined by the loading process from free space to waveguide confinement. Here, we provide a numerical study of the loading dynamics of cold atoms into a hollow-core photonic crystal fiber. We use the Monte Carlo method to simulate the trajectories of an ensemble of cold atoms from free space trapping potential to optical potential inside a hollow-core fiber and calculate the temperature, loading efficiency, and geometry of the ensemble. We also study the noise sources that cause heating and a loss of atoms during the process. Our result could be used to design and optimize the loading process of cold atoms into a hollow-core fiber for cold atom experiments.

We utilize the dark state in a -type three-level system to cool an ensemble of 85 Rb atoms in an optical lattice [Morigi et al., Phys. Rev. Lett. 85, 4458 (2000)]. The common suppression of the carrier transition of atoms with different vibrational frequencies allows them to reach a subrecoil temperature of 100 nK after being released from the optical lattice. A nearly zero vibrational quantum number is determined from the time-of-flight measurements and adiabatic expansion process. The features of sideband cooling are examined in various parameter spaces. Our results show that dark-state sideband cooling is a simple and compelling method for preparing a large ensemble of atoms into their vibrational ground state of a harmonic potential and can be generalized to different species of atoms and molecules for studying ultracold physics that demands recoil temperature and below.

We investigate a scheme that enhances survival resonances in a δ-killed system through actively recycling lost atoms. The process causes atoms to dissipate into superpositions of momentum states with sustained survival when exposed to kicks of a dissipative optical standing wave. The recycling process causes momentum redistribution, which gives the atoms multiple chances to enter a long-surviving mode. The survival resonance peak height shows an improvement of a factor of 2.4. This technique can increase the sensitivity and precision of atomic interferometers based on survival resonances.