Dark-state polaritons in a five-level $M$ -type atomic ensemble are proposed in the electromagnetically induced transparency. Under conditions of the low excitation limit and adiabatic following, the quantum field can be mapped onto the atomic polarization states, forming the shape preserving quantum states of polaritons. Two channels for robust quantum memory are provided, which enables the potential applications in quantum-information processing.Dark-state polaritons in a five-level $M$-type atomic ensemble are proposed in the electromagnetically induced transparency. Under conditions of the low excitation limit and adiabatic following, the quantum field can be mapped onto the atomic polarization states, forming the shape preserving quantum states of polaritons. Two channels for robust quantum memory are provided, which enables the potential applications in quantum-information processing.

Physical Review AMar 28, 200612 citations

Quantum Memory in Atomic Ensembles

Joshua Nunn

Jan 1, 200810 citations

ATOMIC ENSEMBLE QUANTUM MEMORIES

Shau-Yu Lan, Ruitong Zhao, S. D. Jenkins +7 more

International Conference on Atomic Physics (ICAP)Mar 1, 20090 citations

Efficient multiplexed quantum memory with high-dimensional orbital angular momentum states in cold atoms

Xin Yang, Chengyuan Wang, Jinwen Wang +9 more

Quantum memory plays a pivotal role in the construction of quantum repeaters, which are essential devices for establishing long-distance quantum communications and large-scale quantum networks. To boost information capacity and signal processing speed, the implementation of high-efficiency multiplexed quantum memories is essential for the development of multiplexed quantum repeaters. We experimentally demonstrate an efficient multiplexed quantum memory by consolidating photons carrying high-dimensional orbital angular momentum (OAM) states from four individual channels into an elongated cold Rb87 atomic ensemble. Benefiting from the cold atomic ensemble with high optical depth, we obtain a storage efficiency exceeding 70% for the four-channel multiplexed beam. The storage fidelities surpass 83% when all channels are operated in a four-dimensional Hilbert space, which is far above the classical benchmark and validates the quantum functionality of our memory system. The achieved high-efficiency OAM multiplexed quantum memory opens up an avenue for efficient quantum information processing over multiple parallel channels, promising significant advances in the field of quantum communication and networking.Quantum memory plays a pivotal role in the construction of quantum repeaters, which are essential devices for establishing long-distance quantum communications and large-scale quantum networks. To boost information capacity and signal processing speed, the implementation of high-efficiency multiplexed quantum memories is essential for the development of multiplexed quantum repeaters. We experimentally demonstrate an efficient multiplexed quantum memory by consolidating photons carrying high-dimensional orbital angular momentum (OAM) states from four individual channels into an elongated cold Rb87 atomic ensemble. Benefiting from the cold atomic ensemble with high optical depth, we obtain a storage efficiency exceeding 70% for the four-channel multiplexed beam. The storage fidelities surpass 83% when all channels are operated in a four-dimensional Hilbert space, which is far above the classical benchmark and validates the quantum functionality of our memory system. The achieved high-efficiency OAM multiplexed quantum memory opens up an avenue for efficient quantum information processing over multiple parallel channels, promising significant advances in the field of quantum communication and networking.

arXiv:2503.01106Advanced PhotonicsOct 14, 20256 citations

Quantum Memory, Quantum Phase Gate and Polarization Entangled Photon Pairs in a Coherent Atomic System

Ying Gu, Fuli Li, Qihuang Gong +1 more

It is known that photons are the ideal carriers of quantum information and ensemble of atoms can be acted as the long lived storage and processing units. In the coherently prepared atomic ensemble with the light resonantly interacting with the atoms, various schemes have been proposed to implement quantum state transfer and storage, quantum phase gate, generation of entangled photons, and the long-distance quantum communication [1]. We first proposed the dark-state polaritons in a five-level M-type atomic ensemble in the electro magnetically induced transparency (EIT) [2], Under conditions of the low excitation limit and adiabatic following, the quantum field can be mapped onto the atomic polarization states, forming the shape preserving quantum states of polaritons. Two channels for robust quantum memory are provided. Then, we investigated the nonlinear optical response of a five-level tripod atomic system in the EIT, and proposed a three-qubit phase gate protocol based on the fifth-order nonlinearity [3]. The cross phase modulation among three weak fields induced by the fifth-order nonlinearity in EIT can produce the phase shift of order n, which can be used to realize the three-qubit polarization phase gate. Finally, we proposed a cavity-QED scheme that can effectively generate EPR polarization-entangled photon pairs [4], A four-level tripod atom successively couples to two high-Q optical cavities possessing polarization degeneracy, assisted by a classical π-polarized pump field. The stimulated Raman adiabatic passage process in the atom-cavity system is used to produce the polarization-entangled photon pairs. The proposal is particularly robust against atomic spontaneous decay. The above protocols should have potential applications in quantum information processing.It is known that photons are the ideal carriers of quantum information and ensemble of atoms can be acted as the long lived storage and processing units. In the coherently prepared atomic ensemble with the light resonantly interacting with the atoms, various schemes have been proposed to implement quantum state transfer and storage, quantum phase gate, generation of entangled photons, and the long-distance quantum communication [1]. We first proposed the dark-state polaritons in a five-level M-type atomic ensemble in the electro magnetically induced transparency (EIT) [2], Under conditions of the low excitation limit and adiabatic following, the quantum field can be mapped onto the atomic polarization states, forming the shape preserving quantum states of polaritons. Two channels for robust quantum memory are provided. Then, we investigated the nonlinear optical response of a five-level tripod atomic system in the EIT, and proposed a three-qubit phase gate protocol based on the fifth-order nonlinearity [3]. The cross phase modulation among three weak fields induced by the fifth-order nonlinearity in EIT can produce the phase shift of order n, which can be used to realize the three-qubit polarization phase gate. Finally, we proposed a cavity-QED scheme that can effectively generate EPR polarization-entangled photon pairs [4], A four-level tripod atom successively couples to two high-Q optical cavities possessing polarization degeneracy, assisted by a classical π-polarized pump field. The stimulated Raman adiabatic passage process in the atom-cavity system is used to produce the polarization-entangled photon pairs. The proposal is particularly robust against atomic spontaneous decay. The above protocols should have potential applications in quantum information processing.

OSA Workshop on Entanglement and Quantum DecoherenceJan 1, 20080 citations

A single-atom quantum memory

Holger Specht, Christian Nölleke, Andreas Reiserer +4 more

arXiv:1103.1528NatureApr 28, 2011443 citations

Dark-state polaritons in a five-level

M

-type atomic ensemble are proposed in the electromagnetically induced transparency. Under conditions of the low excitation limit and adiabatic following, the quantum field can be mapped onto the atomic polarization states, forming the shape preserving quantum states of polaritons. Two channels for robust quantum memory are provided, which enables the potential applications in quantum-information processing.