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arXiv · 1806.04014

Extended Coulomb liquid of paired hardcore boson model on a pyrochlore lattice

Chun-Jiong Huang·Changle Liu·Ziyang Meng·Yue Yu·Youjin Deng·Gang Chen
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Abstract

There is a growing interest in the $U(1)$ Coulomb liquid in both quantum materials in pyrochlore ice and cluster Mott insulators and cold atom systems. We explore a paired hardcore boson model on a pyrochlore lattice. This model is equivalent to the XYZ spin model that was proposed for rare-earth pyrochlores with "dipole-octupole" doublets. Since this model has no sign problem for quantum Monte Carlo (QMC) simulations in a large parameter regime, we carry out both analytical and QMC calculations. We find that the $U(1)$ Coulomb liquid is quite stable and spans a rather large portion of the phase diagram with boson pairing. Moreover, we numerically find thermodynamic evidence that the boson pairing could induce a possible $\mathbb{Z}_2$ liquid in the vicinity of the phase boundary between Coulomb liquid and $\mathbb{Z}_2$ symmetry-broken phase. Besides the materials' relevance with quantum spin ice, we point to quantum simulation with cold atoms on optical lattices.

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Chun-Jiong Huang, Changle Liu, Ziyang Meng, Yue Yu, Youjin Deng, Gang Chen. 2018-06-11. Extended Coulomb liquid of paired hardcore boson model on a pyrochlore lattice. https://doi.org/10.1103/physrevresearch.2.042022

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