First-order phase transition and tricritical point in multiband U(1) London superconductors
Abstract
The order of the superconducting phase transition is a classical problem. Single-component type-2 superconductors exhibit a continuous "inverted-XY" phase transition, as was first demonstrated for U(1) lattice London superconductors by a celebrated duality mapping with subsequent backing by numerical simulations. Here we study this problem in multiband U(1) London superconductors and find evidence that by contrast the model has a tricritical point. The superconducting phase transition becomes first-order when the Josephson length is sufficiently large compared to the magnetic field penetration length. We present evidence that the fluctuation-induced dipolar interaction between vortex loops makes the phase transition discontinuous. We discuss that this mechanism is also relevant for the phase transitions in multicomponent gauge theories with higher broken symmetry.
Keywords
Cite
@article{arxiv.1508.02311,
title = {First-order phase transition and tricritical point in multiband U(1) London superconductors},
author = {Karl A. H. Sellin and Egor Babaev},
journal= {arXiv preprint arXiv:1508.02311},
year = {2016}
}
Comments
Four-band results added (fig. 4). 6 pages, 5 figures