Open AccessCoherent generation and manipulation of entangled stationary photons based on a multiple degrees of freedom quantum memory
Author(s) -
Tianhui Qiu,
H Li,
Mei Xie,
Q Liu
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.027477
Subject(s) - physics , quantum entanglement , photon entanglement , photon , quantum mechanics , quantum teleportation , degrees of freedom (physics and chemistry) , polarization (electrochemistry) , quantum , angular momentum , quantum channel , quantum sensor , quantum information , photon polarization , spontaneous parametric down conversion , quantum information science , quantum network , chemistry
We propose a quantum memory, each subsystem of which is comprised of two double M-type systems of cold atoms, for the first generation of entangled stationary photons (ESPs). Through the active operation of two pairs of counter-propagating controlling fields in time, the reversible transfer of entanglement between photons and atomic ensembles is realized, and the ESPs can be created due to the tight coupling and balanced competition between the corresponding retrieved signal photons. The reduced density matrix in the photon-polarization basis, which provides the lower bound for any purported entanglement, is constructed for discussing the dynamics evolution of the entanglement in terms of the concurrence. We show that the present scheme can be employed for the entangled photons encoded in degrees of freedom (DOFs) of polarization and orbital angular momentum. Such a multiple DOFs dependent scheme, with many benefits over that in a single one, could pave the way toward quantum nonlinear optics without a cavity and could greatly enhance the tunability and capacity for the quantum information processing.