Pairwise entanglement and readout of atomic-ensemble and optical wave-packet modes in traveling-wave Raman interactions

Abstract

We analyze quantum entanglement of Stokes light and atomic electronic polarization excited during single-pass, linear-regime, stimulated Raman scattering in terms of optical wave-packet modes and atomic-ensemble spatial modes. The output of this process is confirmed to be decomposable into multiple discrete, bosonic mode pairs, each pair undergoing independent evolution into a two-mode squeezed state. For this we extend the Bloch-Messiah reduction theorem, previously known for discrete linear systems (S. L. Braunstein, Phys. Rev. A, vol. 71, 055801 (2005)). We present typical mode functions in the case of one-dimensional scattering in an atomic vapor. We find that in the absence of dispersion, one mode pair dominates the process, leading to a simple interpretation of entanglement in this continuous-variable system. However, many mode pairs are excited in the presence of dispersion-induced temporal walkoff of the Stokes, as witnessed by the photon-count statistics. We also consider the readout of the stored atomic polarization using the anti-Stokes scattering process. We prove that the readout process can also be decomposed into multiple mode pairs, each pair undergoing independent evolution analogous to a beam-splitter transformation. We show that this process can have unit efficiency under realistic experimental conditions. The shape of the output light wave packet can be predicted. In case of unit readout efficiency it contains only excitations originating from a specified atomic excitation mode.

Cited by in corpus (22)

• Mapping broadband single-photon wavepackets into an atomic memory
• Modematching an optical quantum memory
• Theory of quantum frequency conversion and type-II parametric down-conversion in the high-gain regime
• High-performance Raman quantum memory with optimal control
• A Cavity-Enhanced Room-Temperature Broadband Raman Memory
• Temporal Modes in Quantum Optics: Then and Now
• Interference of two photons of different color
• Multi-pulse addressing of a Raman quantum memory: configurable beam splitting and efficient readout
• Theory of noise suppression in Λ-type quantum memories by means of a cavity
• Theory of quantum frequency translation of light in optical fiber: application to interference of two photons of different color
• Hamiltonian design in readout from room-temperature Raman atomic memory
• Coherent perfect absorption of quantum light
• Coherent spin-wave processor of stored optical pulses
• Spectral theory of quantum memory and entanglement via Raman scattering of light by an atomic ensemble
• Noise-induced topological transformations of vortex solitons in optical fibers filled with a cold atomic gas
• Quantum memory in an optical lattice
• Eigenmode description of Raman scattering in atomic vapors in the presence of decoherence
• Mesoscopic entanglement of atomic ensembles through non-resonant stimulated Raman scattering
• Correlation enhanced phase sensitive Raman scattering in atomic vapors
• Multimode Raman light-atom interface in warm atomic ensemble as multiple three-mode quantum operations
• Photon--Matter Quantum Correlations in Spontaneous Raman Scattering
• Electromagnetically-induced transparency assists the Raman gradient echo memory at moderate detuning, dependent on gradient order