Volume 86, Number 5, June 2009
Article Number 50005
Number of page(s) 5
Section General
Published online 24 June 2009
EPL, 86 (2009) 50005
DOI: 10.1209/0295-5075/86/50005

Quantum amplitude amplification by phase noise

M. Sadgrove

Institute of Laser Science, The University of Electro-Communication 1-5-1 Chofugaoka, Chofu, 182-8585, Japan

received 31 March 2009; accepted in final form 15 May 2009; published June 2009
published online 24 June 2009

I consider a system in which an atom in a superposition of momentum eigenstates of a periodic potential is subject to periodic random phase jumps in that potential. If the j-th state in superposition is “marked" by giving the (j-1)-th state a phase flip, I show that for the correct amount of noise, a ~ 6 dB amplification of the marked state probability amplitude occurs, with no significant amplification in other states.

03.67.Ac - Quantum algorithms, protocols, and simulations.
03.75.-b - Matter waves.
05.40.Ca - Noise.

© EPLA 2009