Jan 28, 2020 3:45 pm - Nielsen Hall 170 (Neal F. Lane Auditorium) - Colloquium
Julia Wildeboer - Arizona State University
Quantum many-body physics beyond the ground state

The thermodynamic description of many-body systems relies on the assumption of ergodicity which refers to the ability of a system to explore all allowed configurations in its phase space. However, recent studies have revealed the existence of systems that violate ergodicity either strongly or weakly. While the phenomenon of many-bodylocalization is responsible for strong ergodicity breaking, this talk will focus on weakly broken ergodicity governed by a different mechanism. Here the presence of special eigenstates --called quantum many-body scar states-- in the many-body spectrum defying the eigenstate thermalization hypothesis (ETH) is identified as said mechanism. Constrained models with dimer degrees of freedom have been known as a powerhouse of statistical physics and various branches of theoretical and mathematical physics, in particular aspects of quantum magnetism, for a long time. In this talk I will show how topological quantum many-body scars naturally arise in a quantum dimer model on the kagome lattice and discuss several properties of this model. As time permits I will comment on general construction schemes that will allow for designing many-body Hamiltonians that capture the interesting newly discovered phenomenon of scar states.