Enhancement of coherence in qubits due to interaction with environment

TL;DR

This paper investigates how initial preparation and qubit-environment interactions can enhance qubit coherence, revealing that certain measurements induce significant initial coherence improvements in open quantum systems.

Contribution

It introduces an exactly solvable model showing that specific non-selective preparations can significantly boost qubit coherence through qubit-bath correlations.

Findings

Initial coherence enhancement depends on preparation measurements.

Coherence increases at the initial stage of evolution.

Temperature and coupling strength affect coherence dynamics.

Abstract

The influence of the initial preparation on dephasing in open quantum dynamics is studied using an exactly solvable model of a two-level system (qubit) interacting with a bosonic bath. It is found that for some classes of non-selective preparation measurements, qubit-bath correlations lead to a significant enhancement of coherence in the qubit at the initial stage of evolution. The time behavior of the qubit purity and entropy in the regime of enhancement of coherence is considered for different temperatures and coupling strengths.