Year: 2026
Type: preprint
Abstract: We present a UV-complete model with a global $U(1)$ symmetry in $d=2+1$ dimensions that exhibits a Berezinskii-Kosterlitz-Thouless (BKT) ordered phase at arbitrarily high temperatures. A careful separation of scales yields a two-dimensional Euclidean effective field theory whose construction remains perturbatively controlled even when its soft modes become strongly coupled. We determine the BKT phase boundary by carefully matching this theory to existing lattice Monte Carlo results. The high-temperature phase supports gapless static modes and algebraically decaying correlations even as $T\to\infty$.
Source: arXiv (Cornell University)
Authors: Chowdhury, Subham Dutta, Miro, Joan Elias
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223407746