Using unitary operations to preserve quantum states in the presence of relaxation

TL;DR

This paper presents a general method using unitary operations to maintain specific non-equilibrium quantum states in systems experiencing relaxation, demonstrated through examples involving one-spin and two-spin entangled systems.

Contribution

It introduces a novel principle for using unitary operations to preserve quantum states during relaxation in arbitrary quantum systems.

Findings

Unitary operations can effectively preserve quantum states during relaxation.

The method is demonstrated with examples involving one-spin and two-spin entangled systems.

The approach offers a new way to maintain quantum information in noisy environments.

Abstract

When a quantum system interacts with an external environment, it undergoes the loss of quantum correlation (decoherence) and the loss of energy (relaxation) and eventually all of the quantum information becomes classical. Here we show a general principle to use unitary operations to establish and preserve particular non-equilibrium states in arbitrary relaxing quantum systems. We elucidate these concepts with examples of state preservation in one-spin and two-spin entangled systems.