Princeton University

School of Engineering & Applied Science

Dynamic Phase Transitions, Photocurrents and Exotic Quantum Phases in Ultracold Atom Systems

Ludwig Mathey, University of Hamburg
Engineering Quadrangle B327
Tuesday, July 23, 2013 - 12:00pm to 1:00pm


In this talk I present several recent projects on many-body effects in ultra cold atom systems. These versatile systems can be used to study phase transitions and ordering in a well-controlled environment. A recent joint experimental and theoretical study of the fully frustrated triangular lattice realizes a phase transition in which a chiral order is generated. This order can be controlled via an artificial gauge field, created via lattice shaking. In another joint recent work we create the equivalent of photocurrents in a lattice, and map out the dynamics of both the fermions and the holes via band mapping. The dynamics can be understood with a semi-classical description of a generalized pendulum equation. Furthermore, we propose to investigate the quantum phases of dipolar Fermi gases in optical lattices. In particular, we predict a novel bond order solid phase, that can be realized under realistic conditions. Finally we propose to induce dynamic phase transition in these systems, in particular a dynamic Kosterlitz Thouless transition. Its time evolution can be detected via matter wav interferometry, and can be theoretically understood with a real-time renormalization group approach.


Ludwig Mathey obtained his diploma from the University of Heidelberg, and then pursued his graduate studies at Harvard University, where he worked in the field of many-body theory of ultra cold atom systems. After graduating in 2007, he joined the Joint Quantum Institute of the National Institute of Standards and Technology (NIST) and the University of Maryland for a postdoctoral position. In 2011 he accepted an assistant professorship at the Institute for Laser Physics at the University of Hamburg. The main focus of his research group is the physics of solid state and ultra cold atom systems, as well as general questions of many-body physics.