Decoherence suppression via environment preparation

TL;DR

This paper explores how preparing the environment's initial state can prevent or minimize decoherence in a quantum system, identifying conditions for decoherence-free evolution and optimal initial states.

Contribution

It provides a theoretical condition for the existence of environment states that enable decoherence-free evolution in two-state quantum systems.

Findings

Decoherence-free states exist if the interaction and self-evolution Hamiltonians share an eigenstate.

When decoherence prevention by environment preparation isn't possible, optimal states minimize decoherence.

The results clarify the relationship between environment states and decoherence control in quantum systems.

Abstract

To protect a quantum system from decoherence due to interaction with its environment, we investigate the existence of initial states of the environment allowing for decoherence-free evolution of the system. For models in which a two-state system interacts with a dynamical environment, we prove that such states exist if and only if the interaction and self-evolution Hamiltonians share an eigenstate. If decoherence by state preparation is not possible, we show that initial states minimizing decoherence result from a delicate compromise between the environment and interaction dynamics.