# CAMP Seminar: Emergent ground-state solution to quantum dynamics far from equilibrium

## Main Content

The far-from-equilibrium dynamics of quantum many-body systems has become an active research area in recent years. Remarkable experimental and theoretical breakthroughs in different fields, such as ultracold atoms, photonic systems, and condensed matter, have demonstrated, among other things, that it is possible to dynamically create novel quantum states of matter that do not exist in equilibrium. I will introduce a new paradigm for quantum systems far from equilibrium: the generation of time-evolving states that are eigenstates of emergent local Hamiltonians [1]. The term ‘emergent’ is used in the sense that the Hamiltonian is not trivially related to the one driving the dynamics. Hence, this paradigm provides a means for realizing novel quantum states.

As an example, I will discuss a counter-intuitive outcome of nonequilibrium dynamics in which quantum coherence, absent in the initial state, is generated dynamically. I will focus on a recent experiment with strongly interacting ultracold bosons, confined in one-dimensional optical lattices [2]. While the initial state exhibited no or little coherence, the experiment demonstrated a dynamical generation of peaks in the momentum distribution function that are consistent with (quasi)condensation at finite momenta. The simple but powerful paradigm introduced in my talk can help understanding this phenomenon and, more generally, the emergence of ground-state features in a wide range of dynamical problems involving transport.

[1] L. Vidmar, D. Iyer, M. Rigol, arXiv:1512.05373 (2016)

[2] L. Vidmar, J.P. Ronzheimer, M. Schreiber, S. Braun, S.S. Hodgman, S. Langer, F. Heidrich-Meisner, I. Bloch, U. Schneider, Phys. Rev. Lett. 115, 175301 (2015)