Title: High-temperature Gibbs states are unentangled and efficiently preparable
Abstract: We show that thermal states of local Hamiltonians are separable above a constant temperature. Specifically, for a local Hamiltonian H on a graph with degree d, its Gibbs state at inverse temperature beta is a classical distribution over product states for all beta smaller than 1/(cd), where c is a constant. This proof of "sudden death of thermal entanglement" resolves the fundamental question of whether many-body systems can exhibit entanglement at high temperature.
Joint work with Ainesh Bakshi, Allen Liu, and Ankur Moitra.