Coherence protection in coupled quantum systems

TL;DR

This paper demonstrates that in coupled quantum systems with different energy scales, one part can remain coherent despite environmental interactions, and coherence can even improve with increased bath coupling or temperature, aiding quantum computer design.

Contribution

It introduces a novel decoherence protection mechanism in coupled quantum systems with different energy scales, enabling more robust quantum information processing.

Findings

Protection of coherence in one part despite environmental interaction

Coherence can increase with stronger bath coupling or higher temperature

Potential for designing decoherence-resistant hybrid quantum computers

Abstract

The interaction of a quantum system with its environment causes decoherence, setting a fundamental limit on the suitability of a system for quantum information processing. However, we show that if the quantum system consists of coupled parts with different internal energy scales then the interaction of one part with a thermal bath need not lead to loss of coherence from the other. Remarkably, we find that the protected part can become more coherent when the coupling to the bath becomes stronger or the temperature is raised. Our theory will enable the design of decoherence-resistant hybrid quantum computers.