Researchers chart collective entanglement in quantum matter

Researchers at the Université de Montréal and Perimeter Institute for Theoretical Physics have developed tools to identify a specific form of quantum entanglement, Genuine Network Multiparty Entanglement (GNME), revealing its surprising behavior in complex materials. Their work demonstrates a sharp peak of GNME in the 1D transverse field Ising model precisely at its critical phase transition, with entanglement rapidly diminishing elsewhere. The study further shows that while certain 2D quantum spin liquids exhibit strong Genuine Multiparty Entanglement (GME), they possess no GNME in microscopic regions, suggesting a distinction between different types of collective entanglement. This approach will allow them to chart truly collective entanglement in quantum matter both in and out of equilibrium. Genuine network multiparty entanglement (GNME) offers a method for identifying truly collective entanglement by analyzing whether a multi-particle state requires resources beyond simple paired connections. Unlike standard approaches to gauging collective entanglement via genuine multiparty entanglement (GME), GNME systematically addresses limitations arising from area laws observed in ground and thermal states of local Hamiltonians. These area laws often obscure key properties encoded in subleading terms, necessitating…