Interaction induced breakdown of topological pumping

Anne-Sophie Walter, Zijie Zhu, Marius Gächter, Joaquín Minguzzi, Stephan Roschinski, Kilian Sandholzer, Konrad Viebahn, Tilman Esslinger
ETH Zurich, Switzerland

Cold atoms in a periodically varying lattice potential can serve as a platform to study quantum transport. By adiabatically varying certain parameters of such a one dimensional lattice system, a fermionic cloud of atoms can realize the paradigmatic Thouless pump. The slow variation then leads to the atoms being transported an integer number of lattice sites per pump cycle. The quantisation of transport solely depends on the topology of the trajectory in parameter space and is therefore robust against disorder and other perturbations. Here we investigate the competition between this topological protection and on-site interactions in a system of ultra-cold fermionic atoms.