Many-body entanglement: a look from the tower (of states)
Tommaso Roscilde (Ecole Normale Supérieure de Lyon)
Hybrid seminar: onsite + zoom.
Meeting ID: 937 2220 1378
The non-equilibrium dynamics of many-body quantum systems is among the most effective mechanisms for the production of entanglement. The general paradigm of entanglement dynamics involves the propagation of finite-momentum quasi-particle excitations, which propagate ballistically and generate correlations within a causal cone around every point in space. In fact this picture is rather incomplete, as it neglects the existence of zero-momentum excitations: such excitations are dominant at low energy in systems breaking spontaneously a continuous symmetry, and they form the so-called Anderson tower of states. In this talk I will discuss how the low-energy tower of states in spin models can be effectively described within an approximate separation of variables between finite- and zero-momentum excitations; and how such states are responsible for the dramatic entanglement dynamics observed in U(1) symmetric models — most importantly, dipolar spin systems realized in Rydberg-atom arrays — which develop a cascade of multipartite entangled states completely missed by any quasiparticle picture.