# Thermalization as an Invisibility Cloak for Fragile Quantum Superpositions

## TL;DR

This paper introduces a method that uses thermalization and Loschmidt echo to protect fragile quantum superpositions from dephasing, effectively rendering them invisible to external noise in many-particle systems.

## Contribution

It presents a novel approach combining thermalization dynamics with time reversal to shield fragile quantum states from external dephasing effects.

## Key findings

- Thermalization makes superposed states indistinguishable during the process.
- The method effectively protects quantum superpositions in spin systems.
- Validation performed on a spin-1/2 cluster demonstrates feasibility.

## Abstract

We propose a method for protecting fragile quantum superpositions in many-particle systems from dephasing by external classical noise. We call superpositions "fragile" if dephasing occurs particularly fast, because the noise couples very differently to the superposed states. The method consists of letting a quantum superposition evolve under the internal thermalization dynamics of the system, followed by a time reversal manipulation known as Loschmidt echo. The thermalization dynamics makes the superposed states almost indistinguishable during most of the above procedure. We validate the method by applying it to a cluster of spins-1/2.