Electromagnetically induced quantum memory

Jesse L Everett

Spectrotemporal encoding of optical quantum information is emerging as a powerful tool in quantum information technology. Processing of spectrotemporal information has recently been demonstrated in multi-mode quantum memories, based on extensions to memory protocols. We simulate one such process, the fractional Fourier transform, in a system based on a dual quantum memory composed of successive gradient echo memory and electromagnetically-induced transparency operations. We demonstrate the potential of electromagnetically-induced transparency systems for spectrotemporal processing.

Wolfgang Tittel, Mikael Afzelius, Nicolas Gisin +2 more

Lijun Ma, Oliver Slattery, Xiao Hong Tang

Electromagnetically induced transparency (EIT) is a promising approach to implement quantum memory in quantum communication and quantum computing applications. In this paper, following a brief overview of the main approaches to quantum memory, we provide details of the physical principle and theory of quantum memory based specifically on EIT. We discuss the key technologies for implementing quantum memory based on EIT and review important milestones, from the first experimental demonstration to current applications in quantum information systems.

Ran Zhao, T. Chanelière, Dzmitry Matsukevich +4 more

Xiong-Jun Liu, Zheng-Xin Liu, Xin Liu +1 more

We study the effect of inhomogeneous coupling between atoms and external light fields on quantum memories that employ electromagnetically induced transparency (EIT). By introducing atomic subensembles to describe the present inhomogeneous coupling case we find that there is a nonsymmetric dark-state subspace that allows the EIT quantum-memory technique to function perfectly. This shows that such a memory scheme can work ideally even if the atomic state is very far from being a symmetric one.