Restoring coherence lost to a slow interacting mesoscopic spin bath

Phys Rev Lett. 2007 Feb 16;98(7):077602. doi: 10.1103/PhysRevLett.98.077602. Epub 2007 Feb 12.

Abstract

For a two-state quantum object interacting with a slow mesoscopic interacting spin bath, we show that a many-body solution of the bath dynamics conditioned on the quantum-object state leads to an efficient control scheme to recover the lost quantum-object coherence through disentanglement. We demonstrate the theory with the realistic problem of one electron spin in a bath of many interacting nuclear spins in a semiconductor quantum dot. The spin language can be easily generalized to a quantum object in contact with a bath of interacting multilevel quantum units with the caveat that the bath is mesoscopic and its dynamics is slow compared with the quantum object.