Topological pumping in the strongly correlated regime

A topological pump can be regarded as the one-dimensional counterpart to the quantum Hall effect, in which time plays the role of a second dimension. Quantisation of charge transport is achieved by slowly encircling a topological transition point in Hamiltonian parameter space. Previously, topological pumps have been realised with non-interacting and mean-field states in synthetic quantum systems, such as ultracold atoms and photonics. However, the fate of quantised pumping in the strongly correlated regime has remained out of reach to date. Here, we present recent experimental progress towards investigating the effects of Hubbard interactions on topological charge transport of ultracold fermions. Our measurements suggest significant deviations from the quantised value for attractive and repulsive interactions. We compare our results to recent theoretical studies that predict a breakdown of pumping in the Mott regime.