Abstract
The Berezinskii-Kosterlitz-Thouless (BKT) transition is the paradigmatic example of a topological phase transition without symmetry breaking, where a quasiordered phase, characterized by a power-law scaling of the correlation functions at low temperature, is disrupted by the proliferation of topological excitations above the critical temperature . In this Letter, we consider the effect of long-range decaying couplings on the BKT transition. After pointing out the relevance of this nontrivial problem, we discuss the phase diagram, which is far richer than the corresponding short-range one. It features—for —a quasiordered phase in a finite temperature range , which occurs between a symmetry broken phase for and a disordered phase for . The transition temperature displays unique universal features quite different from those of the traditional, short-range model. Given the universal nature of our findings, they may be observed in current experimental realizations in 2D atomic, molecular, and optical quantum systems.
- Received 17 May 2021
- Accepted 16 August 2021
DOI:https://doi.org/10.1103/PhysRevLett.127.156801
© 2021 American Physical Society