Manipulation and storage of optical field and atomic ensemble quantum states (original) (raw)

Entanglement of Atomic Ensembles by Trapping Correlated Photon States

Physical Review Letters, 2000

We describe a general technique that allows for an ideal transfer of quantum correlations between light fields and metastable states of matter. The technique is based on trapping quantum states of photons in coherently driven atomic media, in which the group velocity is adiabatically reduced to zero.

Entanglement storage in atomic ensembles

Europhysics Letters (EPL), 2004

67.-a -Quantum information. PACS. 03.67.Mn -Entanglement production, characterization and manipulation. PACS. 42.50.Lc -Quantum fluctuations, quantum noise and quantum jumps.

Quantum engineering of photon states with entangled atomic ensembles

Arxiv preprint arXiv:0704.0641, 2007

We propose and analyze a new method to produce single and entangled photons which does not require cavities. It relies on the collective enhancement of light emission as a consequence of the presence of entanglement in atomic ensembles. Light emission is triggered by a laser pulse, and therefore our scheme is deterministic. Furthermore, it allows one to produce a variety of photonic entangled states by first preparing certain atomic states using simple sequences of quantum gates. We analyze the feasibility of our scheme, and particularize it to: ions in linear traps, atoms in optical lattices, and in cells at room temperature.

How to trap photons? Storing single-photon quantum states in collective atomic excitations

Optics Communications, 2000

We s h o w that it is possible to \store" quantum states of single-photon elds by mapping them onto collective meta-stable states of an optically dense, coherently driven medium inside an optical resonator. An adiabatic technique is suggested which a l l o ws to transfer non-classical correlations from traveling-wave single-photon wave-packets into atomic states and vise versa with nearly 100% e ciency. I n c o n trast to previous approaches involving single atoms, the present t e c hnique does not require the strong coupling regime corresponding to high-Q micro-cavities. Instead, intracavity Electromagnetically Induced Transparency is used to achieve a strong coupling between the cavity mode and the atoms.

Dissipative Preparation of Spin Squeezed Atomic Ensembles in a Steady State

Physical Review Letters, 2013

We present and analyze a new approach for the generation of atomic spin squeezed states. Our method involves the collective coupling of an atomic ensemble to a decaying mode of an open optical cavity. We demonstrate the existence of a collective atomic dark-state, decoupled from the radiation field. By explicitly constructing this state we find that it can feature spin squeezing bounded only by the Heisenberg limit. We show that such dark states can be deterministically prepared via dissipative means, thus turning dissipation into a resource for entanglement. The scaling of the phase sensitivity taking realistic imperfections into account is discussed.

Teleportation of an atomic ensemble quantum state

2009

We propose a protocol to achieve high fidelity quantum state teleportation of a macroscopic atomic ensemble using a pair of quantum-correlated atomic ensembles. We show how to prepare this pair of ensembles using quasiperfect quantum state transfer processes between light and atoms. Our protocol relies on optical joint measurements of the atomic ensemble states and magnetic feedback reconstruction.

Quantum memory with optically trapped atoms

Physical review letters, 2008

We report the experimental demonstration of a quantum memory for collective atomic states in a far-detuned optical dipole trap. Generation of the collective atomic state is heralded by the detection of a Raman scattered photon and accompanied by storage in the ensemble of atoms. The optical dipole trap provides confinement for the atoms during the quantum storage while retaining the atomic coherence. We probe the quantum storage by cross-correlation of the photon pair arising from the Raman scattering and the retrieval of the atomic state stored in the memory. Non-classical correlations are observed for storage times up to 60 µs.

Light qubit storage and retrieval using macroscopic atomic ensembles

Physical Review A, 2006

We present an experimentally feasible protocol for the complete storage and retrieval of arbitrary light states in an atomic quantum memory using the well-established Faraday interaction between light and matter. Our protocol relies on multiple passages of a single light pulse through the atomic ensemble without the impractical requirement of kilometer long delay lines between the passages. Furthermore, we introduce a time dependent interaction strength which enables storage and retrieval of states with arbitrary pulse shapes. The fidelity approaches unity exponentially without squeezed or entangled initial states, as illustrated by explicit calculations for a photonic qubit.