BKT-paired phase in coupled XY models
Abstract
We study the effect of a linear tunneling coupling between 2D systems, each separately exhibiting the topological Berezinskii-Kosterlitz-Thouless (BKT) transition. In the uncoupled limit, there are two phases: one where the 1-body correlation functions are algebraically decaying and the other with exponential decay. When the linear coupling is turned on, a third BKT-paired phase emerges, in which 1-body correlations are exponentially decaying, while 2-body correlation functions exhibit power-law decay. We perform numerical simulations in the paradigmatic case of two coupled XY models at finite temperature, finding that for any finite value of the interlayer coupling, the BKT-paired phase is present. We provide a picture of the phase diagram using a renormalization group approach.
Keywords
Cite
@article{arxiv.1907.06253,
title = {BKT-paired phase in coupled XY models},
author = {Giacomo Bighin and Nicolò Defenu and István Nándori and Luca Salasnich and Andrea Trombettoni},
journal= {arXiv preprint arXiv:1907.06253},
year = {2019}
}
Comments
6 pages, 1 figure, submitted version