Restoring Coherence Lost to a Slow Interacting Mesoscopic Bath

TL;DR

This paper presents a method to restore quantum coherence in a two-state system interacting with a slow, mesoscopic, interacting spin bath by using a many-body solution of the bath dynamics conditioned on the system state.

Contribution

It introduces an efficient control scheme based on many-body bath dynamics to recover coherence, demonstrated on a realistic quantum dot model.

Findings

Effective coherence recovery through disentanglement.

Applicable to mesoscopic, slow-interacting quantum baths.

Generalizable to multi-level quantum systems.

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 is easily generalized to a quantum object in contact with a bath of interacting multi-level quantum units with the caveat that it is mesoscopic and its dynamics is slow compared with the quantum object.