Condensed Matter Theory Seminar | September 30, 10:00

Quantum Soft Matter with Cold Polar Molecules: Glass and the Hexatic Phase


The realization of cold ensembles of polar molecules has opened a new pathway to explore the dynamics of quantum many body systems with strong, long-range and anisotropic dipolar interactions. While theoretical studies have so far focused on the equilibrium phases in the highly degenerate quantum regime , I will focus in my talk on non-equilibirum dynamics in the regime where quantum and thermal fluctuations are of the same order of magnitude. I will present two proposals: i.) a study on the glass transition in the presence of quantum fluctuations and ii.) a study on quantum fluctuations in the hexatic phase. i.) I will show, how the glass phase can be prepared in a bilayer system of ultracold dipolar molecules and present results on classical and quantum glassy behavior, characterized by long tails in the relaxation time and dynamical heterogeneity. I will also present experimental accessible order parameters based on marker molecules, distinguished by properly chosen internal levels, and find quantum features of dynamical heterogeneity. ii.) The hexatic phase is an intermediate phase in two dimensional systems when going from the crystal to the liquid phase. I will present results on the influence of quantum fluctuations on the nature of the hexatic phase and methods that allow one to measure these effects in a setup with polar molecules.


Wolfgang Lechner, University of Innsbruck
Seminar Room of the Institute for Theoretical Physics
Contact: Philipp Strack