Emergence of Intra-Particle Entanglement and Time-Varying Violation of Bell's Inequality in Dirac Matter

TL;DR

This paper explores how intra-particle entanglement naturally arises and dynamically evolves in Dirac fermions like graphene, leading to time-dependent Bell inequality violations and potential experimental detection.

Contribution

It demonstrates the emergence and dynamics of intra-particle entanglement in Dirac matter, highlighting its independence from initial states and implications for quantum correlations.

Findings

Large intra-particle entanglement in graphene due to spin-orbit coupling

Time-varying violation of Bell's inequality observed

Potential for experimental detection in mesoscopic Dirac devices

Abstract

We demonstrate the emergence and dynamics of intra-particle entanglement in massless Dirac fermions. This entanglement, generated by spin-orbit coupling, arises between the spin and sublattice pseudospin of electrons in graphene. The entanglement is a complex dynamic quantity but is generally large, independent of the initial state. Its time dependence implies a dynamical violation of a Bell inequality, while its magnitude indicates that large intra-particle entanglement is a general feature of graphene on a substrate. These features are also expected to impact entanglement between pairs of particles, and may be detectable in experiments that combine Cooper pair splitting with nonlocal measurements of spin-spin correlation in mesoscopic devices based on Dirac materials.