Quantum correlations in bulk properties of solids obtained from neutron scattering

TL;DR

This paper shows that inelastic neutron scattering can detect quantum correlations like entanglement and discord in magnetic materials, revealing potential for room-temperature quantum devices and the influence of spin-orbit coupling.

Contribution

It introduces a method to measure quantum correlations in solids via neutron scattering and explores the effects of spin-orbit coupling on entanglement and critical temperature.

Findings

Quantum discord persists at room temperature.

Entanglement can be enhanced by spin-orbit coupling.

Critical temperature for entanglement can reach 82.5 K.

Abstract

We demonstrate that inelastic neutron scattering technique can be used to indirectly detect and measure the macroscopic quantum correlations quantified by both entanglement and discord in a quantum magnetic material, VODPO4 . 1D2O. The amount of quantum correlations is obtained 2 by analyzing the neutron scattering data of magnetic excitations in isolated V4+ spin dimers. Our quantitative analysis shows that the critical temperature of this material can reach as high as Tc = 82.5 K, where quantum entanglement drops to zero. Significantly, quantum discord can even survive at Tc = 300 K and may be used in room temperature quantum devices. Taking into account the spin-orbit (SO) coupling, we also predict theoretically that entanglement can be significantly enhanced and the critical temperature Tc increases with the strength of spin-orbit coupling.