Theory Seminar at LMU: Topological two-body bound states

Marco Di Liberto, Université Libre de Bruxelles, Brussels

Marco Di Liberto, Université Libre de Bruxelles, Brussels
LMU München
Theresienstrasse 37, Room A 449
80333 München
Monday, February 17, at 2 p.m.

Bound states of two interacting particles moving on a lattice can exhibit remarkable features that are not captured by the underlying single-particle picture. We will first review several topological phenomena for two-body bound states with onsite interactions. Then, we will introduce a novel framework by which genuine interaction-induced geometric and topological effects can be realized in quantum-engineered systems. Our approach builds on the design of effective lattices for the center-of-mass motion of two-body bound states (doublons), which can be created through long-range interactions. This general scenario is illustrated on several examples, where flat-band localization, topological pumps and higher-order topological corner modes emerge from genuine interaction effects. Our results pave the way for the exploration of interaction-induced topological effects in a variety of platforms, ranging from ultracold gases to interacting photonic devices.

G. Salerno, G. Palumbo, N. Goldman and M. Di Liberto, Interaction-induced lattices for bound states: Designing flat bands, quantized pumps and higher-order topological insulators for doublons, arXiv:1911.05057

G. Salerno, M. Di Liberto, C. Menotti and I. Carusotto, Topological two-body bound states in the interacting Haldane model, Phys. Rev. A 97, 013637 (2018), (arXiv: 1711.01272)

M. Di Liberto, A. Recati, I. Carusotto and C. Menotti, Two-body physics in the Su-Schrieffer-Heeger model, Phys. Rev. A 94, 062704 (2016) (arXiv:1608.07341)