Intertwined entanglement in topological pumps*

We create spatially separated Bell pairs from double occupancies in a fermionic lattice gas using a bidirectional Thouless pump. By controlling the interaction, exactly one atom of the double occupancy occupies the lower and the other the upper band of the topological pump, each experiencing opposite Chern numbers. Topological pumping therefore transports the two correlated components in opposite directions, further separating them with each pumping cycle. During the pumping we apply (SWAP)^a gates, which allow the entangled pairs to pass through each other, giving rise to intertwined entanglement over many lattice sites. As a result, we observe distinctive frequencies and multi-frequency patterns in singlet-triplet oscillations. Perspectives of the scheme for quantum computation, simulation and sensing will be discussed [Z. Zhu, Y. Kiefer, S. Jele, M. Gächter, G. Bisson, K. Viebahn, T. Esslinger, https://arxiv.org/abs/2409.02984 and  Z. Zhu, M. Gächter, A.-S. Walter, K. Viebahn, T. Esslinger, Science 132, 317 (2024)].