# Room-temperature storage of quantum entanglement using decoherence-free subspace in a solid-state spin system

## TL;DR

This paper demonstrates the experimental storage of quantum entanglement at room temperature using a decoherence-free subspace in a solid-state spin system, significantly extending coherence times against collective noise.

## Contribution

It introduces a method to encode entangled states in a decoherence-free subspace of nuclear spins coupled to an NV center, achieving enhanced noise resilience at room temperature.

## Key findings

- Decoherence-free entangled states have coherence times over ten times longer than other states.
- Universal quantum gate control was achieved in a three-qubit system.
- Entanglement storage was successfully demonstrated at room temperature.

## Abstract

We experimentally demonstrate room-temperature storage of quantum entanglement using two nuclear spins weakly coupled to the electronic spin carried by a single nitrogen-vacancy center in diamond. We realize universal quantum gate control over the three-qubit spin system and produce entangled states encoded within the decoherence-free subspace of the two nuclear spins. By injecting arbitrary collective noise, we demonstrate that the decoherence-free entangled state has coherence time longer than that of other entangled states by an order of magnitude in our experiment.