Exploring the nonequilibrium dynamics of ultracold quantum gases by using numerical tools

Numerical tools such as exact diagonalization or the density matrix renormalization group method have been vital for the study of the nonequilibrium dynamics of strongly correlated many-body systems. Moreover, they provided unique insight for the interpretation of quantum gas experiments, whenever a direct comparison with theory is possible. By considering the example of the experiment by Ronzheimer et al.~[1], in which both an interaction quench and the release of bosons from a trap into an empty optical lattice (sudden expansion) was realized, I discuss several nonequilibrium effects of strongly interacting quantum gases. These include the thermalization of a closed quantum system and its connection to the eigenstate thermalization hypothesis [2], nonequilibrium mass transport [1], dynamical fermionization [3], and transient phenomena such as quantum distillation or dynamical quasicondensation [4]. I highlight the role of integrability in giving rise to ballistic transport in strongly interacting 1D systems [1] and in determining the asymptotic state after a quantum quench [5]. The talk concludes with a perspective on open questions concerning 2D systems and the numerical simulation of their nonequilibrium dynamics [6].\\ \noindent [1] Ronzheimer et al., Phys. Rev. Lett. 110, 205301 (2013) \newline [2] Sorg et al., Phys. Rev. A 90, 033606 (2014) \newline [3] Vidmar et al., Phys. Rev. B 88, 235117 (2013) \newline [4] Vidmar et al., Phys. Rev. Lett. 115, 175301 (2015) \newline [5] Mei et al., arXiv:1509.00828 \newline [6] Hauschild, Pollmann, FHM, arXiv:1509.00696