Related papers: Controlled rephasing of single collective spin exc…
To overcome fundamental limitations of the \pi optical pulse-induced population inversion and optical decay-caused short storage time in conventional photon echoes, a coherent control of collective atoms is studied for inversion-free,…
Long-lived quantum memories are essential components of a long-standing goal of remote distribution of entanglement in quantum networks. These can be realized by storing the quantum states of light as single-spin excitations in atomic…
Rephasing in photon echoes is a fundamental mechanism of retrieving optical information stored in a collective ensemble of atoms or ions. With an extremely weak quantum optical data, population inversion by the rephasing process is…
Using collective atom phase control a population inversion-free photon echo scheme has been studied for quantum memory applications. For the inversion-free photon echoes a double rephasing method is combined with optical locking, where the…
We show that coherent multiple light scattering, or diffuse light propagation, in a disordered atomic medium, prepared at ultra-low temperatures, can be be effectively delayed in the presence of a strong control field initiating a…
The photon echo quantum memory is based on a controlled rephasing of the atomic coherence excited by signal light field in the inhomogeneously broadened resonant line. Here, we propose a novel active mechanism of the atomic rephasing which…
Motion-induced dephasing is a dominant decoherence mechanism for atom-gas quantum memories. In this paper, we develop a new coherent manipulation technique which enables arbitrary engineering of the spin-wave momentum with neglectable…
Off-resonant Raman interaction of a single-photon wave packet and a classical control field in an atomic medium with controlled refractive index is investigated. It is shown that a continuous change of refractive index during the…
System consisting of a number of trapped atoms evolving under the influence of external inhomogenous magnetic field undergoes spin dephasing: classically, since each atom feels different field along its trajectory, the spin rotation rates…
Precise control of hyperfine matterwaves via Raman excitations is instrumental to a class of atom-based quantum technology. We investigate the Raman spinor control technique for alkaline atoms in an intermediate regime of single-photon…
We experimentally demonstrate an angularly-multiplexed holographic memory capable of intrinsic generation, storage and retrieval of multiple photons, based on off-resonant Raman interaction in warm rubidium-87 vapors. The memory capacity of…
We examine a quantum memory scheme based on controllable dephasing of atomic coherence of a non-resonant, inhomogeneously broadened Raman transition. We show that it generalizes the physical conditions for time-reversible interaction…
Spin echo is a powerful technique to extend atomic or nuclear coherence time by overcoming the dephasing due to inhomogeneous broadening. However, applying this technique to an ensemble-based quantum memory at single-quanta level remains…
Future quantum repeater architectures, capable of efficiently distributing information encoded in quantum states of light over large distances, will benefit from multiplexed photonic quantum memories. In this work we demonstrate a…
Effective and unrestricted engineering of atom-photon interactions requires precise spatially-resolved control of light beams. The significant potential of such manipulations lies in a set of disciplines ranging from solid state to atomic…
Coherent control of collective spontaneous emission in an extended atomic ensemble resonantly interacting with single-photon wave packets is analyzed. A scheme for coherent manipulation of collective atomic states is developed such that…
We perform Ramsey spectroscopy on the ground state of ultra-cold 87Rb atoms magnetically trapped on a chip in the Knudsen regime. Field inhomogeneities over the sample should limit the 1/e contrast decay time to about 3 s, while decay times…
Photon-echo based optical quantum memory schemes often employ intermediate steps to transform optical coherences to spin coherences for longer storage times. We analyze a scheme that uses three identical chirped control pulses for coherence…
We report a prolonged coherence time of the collective spin wave of a thermal 87Rb atomic ensemble in a paraffin coated cell. The spin wave is prepared through a stimulated Raman Process. The long coherence time time is achieved by…
We perform Raman spectroscopy of optically trapped non interacting \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…