Dynamical Fermionization in 1D Lattice

Nearly integrable one-dimensional gases have been widely used as an experimental platform to study many-body systems in and out of equilibrium. Prominent among the many properties that have been measured in these systems is the distribution of rapidities, which are the momenta of the quasiparticles that describe the interacting gas. In the strongly interacting (Tonks-Girardeau) regime, the rapidity distribution is the same as the momentum distribution of non-interacting fermions, and its measurement is called dynamical fermionization. In this new work, we have added a 1D optical lattice to an array of 1D Bose gases and studied analogous quasi-rapidity distributions.  In the strongly interacting regime, we observe dynamical fermionization in a lattice, which becomes qualitatively different from the free space case as the average site occupation approaches one. The presence of the 1D lattice lifts the integrability of the system for intermediate coupling strengths.  We are studying how this changes rapidity and measured quasi-rapidity distributions, in and out of equilibrium.