Quantum memory is a quantum interaction between an ensemble of multi-particle clusters of atoms and the light that is mapped onto them.This process can be implemented on materials such as cold atoms, ions and crystals with photons usually being the information carrier.Another strategy to store and retrieve quantum information is derived from photon echo, where information is mapped over spectral components of inhomogeneously broadened absorption bands.The use of photonic quantum information allows quantum memory to be equivalent to the memory found in a classical computer.
The proposed advantage of quantum computation hinges on the difference between classical computation by maintaining a non-classical superposition of quantum states. However, when the quantum state is measured, the superposition is lost, making the information classical. In 2007, the concept of an off-resonant atomic quantum memory centered on the idea of a Raman interaction was suggested, and in 2009 was demonstrated by using Caesium vapor kept at room- temperature. The demonstration was capable of storing pulses at 0.3 billionths of a second duration.
The idea of quantum memory becoming a part of long-distance quantum communications or linear optics quantum computation has been experimented with as the use of quantum memory would fit for these applications.
As of 2018, Researchers at Laboratoire Kastler Brossel (LKB) produced 68% efficiency on memory retrieval rates using polarized qubits with 99% conditional fidelity. Qubits were encoded using weak coherent states on a single photon.
Focus on Quantum Memory
Highly-efficient quantum memory for polarization qubits in a spatially-multiplexed cold atomic ensemble
Kun Huang, Alexandra S. Sheremet, Pierre Vernaz-Gris, Mingtao Cao, Julien Laurat
How can you tell if a quantum memory is really quantum?
Physicists use quantum memory to demonstrate quantum secure direct communication
Record-breaking efficiency for secure quantum memory storage
Universite P. et M. Curie
Documentaries, videos and podcasts
Gerodie Rose, and Haig Farris
Quantum computing company
Larry Page, Sergey Brin
Charles Ranlett Flint
Laboratoire Kastler Brossel
Alfred Kastler, and Jean Brossel
Laboratory focused on interactions between light and matter
Dwight D. Eisenhower
Long Island, New York, United States
Creates quantum devices meant to optimize current digital communications
- Quantum computingThe study of computation systems that make use of quantum mechanical phenomena (eg entanglement and superposition). Quantum computers use qubits (rather than binary 0 and 1s) which can be in both states at the same time by being in a superposition of states.
- Cluster: Quantum computingCluster of topics related to quantum computing.