Witnessing spin-orbit thermal entanglement in rare-earth ions

TL;DR

This paper demonstrates that spin-orbit thermal entanglement in rare-earth ions is robust at temperatures far above room temperature, revealing potential for stable quantum states in practical conditions.

Contribution

It introduces a new method to witness spin-orbit entanglement using mean energies and identifies high entanglement temperatures in rare-earth ions.

Findings

Entanglement temperature exceeds 3000 K for light rare earths.

Spin-orbit entanglement persists at high environmental temperatures.

The method provides a robust way to detect internal ion entanglement.

Abstract

We explore spin-orbit thermal entanglement in rare-earth ions, based on a witness obtained from mean energies. The entanglement temperature $T_{E}$, below which entanglement emerges, is found to be thousands of kelvin above room temperature for all light rare earths. This demonstrate the robustness to environmental fluctuations of entanglement between internal degrees of freedom of a single ion.