Interacting frustrated quantum systems represent a rich and challenging playground to unveil novel quantum mechanical effects. After a general overview on this intriguing topic, I will first consider one-dimensional chains where bosonic particles are coupled through competing local and non-local interactions. Here, a numerical analysis demonstrates that unexplored topological matter characterized by localized edge states and gapless bulk excitations can occur. When effective geometrical frustration is further injected in the system, insulators and superfluids peculiar of quantum magnets naturally emerge. In the regime of weak frustration our results show that critical points not predicted by the Landau–Ginzburg-Wilson symmetry-breaking paradigm can connect different insulators. By increasing the level of frustration, the insulators are replaced by a conducting phase where spontaneously generated edge-currents appear. I will show that this state of matter turns out to be a chiral superfluid where topological excitations can take place. Finally, I will discuss how these quantum phenomena and phases can be investigated and probed in ultracold atomic systems.
Seminar: Topology and criticality in frustrated quantum matter, L. Barbiero, Politecnico di Torino, Torino, Italy
July 18, 2023, 11:00 Aula Magna, Dipartimento di Fisica e Astronomia