From Artificial Graphene to Dynamical Lattice Gauge Fields

March 6th, 2019 TILMAN ESSLINGER ETH Zürich

Graphene is a highly controlled and flexible solid-state system that has reinvented material physics. In this talk I will present an artificial quantum many-body system which is akin to graphene, but has other degrees of freedom. We strip down the concept of graphene to its bare bones by implementing a hexagonal optical lattice potential from interfering laser beams and fill it with ultracold fermionic atoms, which take the role of electrons. This graphene-like structure is the starting point for a periodically driven lattice potential in which we break time reversal symmetry and engineer the topological Haldane model, where a transition between topologically distinct phases is marked by the presence of a single Dirac point. Combining the Floquet drive with tunable interactions between the atoms we can engineer the magnetic properties of a strongly interacting Fermi gas in the lattice. Most recently, we used a two-frequency drive to realize a density-dependent Peierls phases, a route to quantum simulation of dynamical lattice gauge fields.

This activity is co-funded by the European Regional Development Funds (ERDF) allocated to the Programa operatiu FEDER de Catalunya 2014-2020, with the support of the Secretaria d’Universitats i Recerca of the Departament d’Empresa i Coneixement of the Generalitat de Catalunya for emerging technology clusters devoted to the valorization and transfer of research results (GraphCAT 001-P-001702).

Wednesday, March 6, 2019, 12:00. ICFO’s Blue Lecture Room

Hosted by Prof. Leticia Tarruell