Physics (Internal)

Using entanglement to solve quantum many particle systems

This event is part of the Physics Department Colloquia Series.

Abstract: What is entanglement? How does understanding entanglement help us to understand quantum systems with many particles? Recent progress has shown that ground states of physical systems have much lower entanglement than they could have. The low entanglement can then become the basis for controlled approximations. The density matrix renormalization group (DMRG) predated this progress, but we now understand that DMRG is the natural and optimal low-entanglement approximation for 1D quantum systems. More generally, "tensor network states" have been developed as the natural low entanglement approximations for higher dimensions. I will review this new understanding of quantum systems, and then illustrate the power of these approaches by discussing our recent progress in finding quantum spin liquids as the ground states of some frustrated magnetic systems.