Title : |
Universal Vortex Properties near the Wilson-Fisher Fixed Point in the (2+1)-d O(2) Model |
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Speaker | : | Uwe-Jens Wiese, University of Bern, Switzerland |
Date | : | April 15, 2021 |
Time | : | 3:30 PM |
Venue | : | Online Google Meet |
Abstract | : |
Vortices arise as topological excitations in superfluids and ultracold quantum gases. Their fully nonperturbative quantization beyond the semiclassical approximation is a nontrivial issue. Upon dualization, the (2+1)-d O(2) model turns into scalar QED, with the vortex being described by a scalar field. The massless Goldstone boson of the spontaneously broken O(2) symmetry then manifests itself as a dual photon. The vortex is a nonlocal infraparticle because it is surrounded by a cloud of massless photons. Its mass is logarithmically infrared divergent because in (2+1)-d the Coulomb potential is logarithmically confining. The Gauss law forbids the existence of a single vortex in a periodic volume. C-periodic boundary conditions introduce a charge conjugation twist and allow the existence of a single vortex in a finite volume without breaking translation invariance. Using numerical simulations, the universal finite-volume vortex mass and vortex charge are then computed accurately in the vicinity of the Wilson-Fisher fixed point. |