Prof. Lode Pollet
LMU Munich, Germany
PhD 2005 Ghent University , PostDoc 2005-2008 ETH Zurich , PostDoc fellow 2008-2010 Univ. Massachusetts/Harvard University, Research Assistant 2010-2011 ETH Zurich, Professor 2011-Now University of Munich.
2018-09-03 - 2018-09-07 Office No:
Inviter: Lei Wang
Contact Person: Contact Number:
|Talk Title: The scratched-XY model in 2D: it is not Kosterlitz-Thouless
Talk Place: M830
Talk Time: 4-Sep-2018 2:00 pm
I show that the 2D classical XY model with disordered scratches can host a new mechanism to destroy superfluidity. As the disorder grows stronger the mechanism driving the superfluid transition changes from conventional vortex-pair unbinding (Kosterlitz-Thouless physics) to a strong randomness criticality characterized by a non-universal jump of the superfluid stiffness. The strong randomness criticality can be described by an asymptotically exact semi-renormalization group theory, previously developed for the superfluid-insulator transition in one-dimensional disordered quantum systems, whose physics I will review. Numerical simulation unambiguously establish that this theory indeed describes the physics of the classical 2D XY model with disordered scratches.