Continuous Easy-Plane Deconfined Phase Transition on the Kagome Lattice

• Published in: Physical review letters Vol. 120; no. 11; p. 115702
• Main Authors: Zhang, Xue-Feng, He, Yin-Chen, Eggert, Sebastian, Moessner, Roderich, Pollmann, Frank
• Format: Journal Article
• Language: English
• Published: United States 16.03.2018
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.120.115702

We use large scale quantum Monte Carlo simulations to study an extended Hubbard model of hard core bosons on the kagome lattice. In the limit of strong nearest-neighbor interactions at 1/3 filling, the interplay between frustration and quantum fluctuations leads to a valence bond solid ground state. The system undergoes a quantum phase transition to a superfluid phase as the interaction strength is decreased. It is still under debate whether the transition is weakly first order or represents an unconventional continuous phase transition. We present a theory in terms of an easy plane noncompact CP^{1} gauge theory describing the phase transition at 1/3 filling. Utilizing large scale quantum Monte Carlo simulations with parallel tempering in the canonical ensemble up to 15552 spins, we provide evidence that the phase transition is continuous at exactly 1/3 filling. A careful finite size scaling analysis reveals an unconventional scaling behavior hinting at deconfined quantum criticality.