Digital quantum memories: storing Schroedinger's cat

2 August 2009

The Schroedinger Cat in quantum mechanics is something in two states at once; both dead and alive. As well as having fundamental interest, these are important in the next generation of quantum sensors, atomic clocks and other quantum technologies.

Swinburne University of Technology researchers Q. He, M. Reid and P. Drummond  have published a new proposed architecture for quantum memories, allowing faithful storage of any  Schroedinger cat state.
 
Previous attempts to build quantum memories have used an analog approach, like a tape-recorder. Instead, Qiongyi He and colleagues propose to build quantum memories using a digital approach, like a computer memory. The proposed digital quantum memory is now published in Optics Express, and is a new paradigm in this field.

Dr He said that the new concept relies on the integration of a microscopic optical cavity with a long-lived quantum oscillator. The key new approach is a tailored gating pulse.

“Our proposed architecture is very adaptable to different technologies. These range from ultra-cold atomic gases at micro or nano-Kelvin temperatures through to superconducting circuits and cooled nano-mechanical oscillators, which can approach the quantum domain”, said Dr He.

The research is funded by the ARC Center of Excellence for Quantum-Atom Optics and SUT CAOUS centre and is a joint project with  University Pierre et Marie Curie, Paris.

See:
Digital quantum memories with symmetric pulses.
Q. Y. He, M. D. Reid, and P. D. Drummond,
Optics Express, 17, 9662 (2009).