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arXiv · 1706.05414

Continuous easy-plane deconfined phase transition on the kagome lattice

Xue-Feng Zhang·Yin-Chen He·Sebastian Eggert·Roderich Moessner·Frank Pollmann
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Abstract

We use large scale quantum Monte-Carlo simulations to study an extended Hubbard model of hardcore 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 NCCP$^1$ 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.

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Xue-Feng Zhang, Yin-Chen He, Sebastian Eggert, Roderich Moessner, Frank Pollmann. 2017-06-16. Continuous easy-plane deconfined phase transition on the kagome lattice. https://doi.org/10.1103/physrevlett.120.115702

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