Speaker: Dr. Chun-Jiong Huang (University of Tennessee, Knoxville)

Time: 14:00, Dec. 20, 2024 (Friday)

Place: No. 2 Meeting Room, 3rd Floor, No. 6 Building (6号楼三层第二会议室)

Abstract:

The Monte Carlo method is a powerful statistical technique for solving strongly correlated systems that are difficult or impossible to address analytically. In this talk, we will focus on the semi-classical Monte Carlo method and its application to explore two spin-1 systems: the bilinear-biquadratic model with an easy-axis single-ion anisotropy on a kagome lattice, and the extended compass model on a square lattice. In the first study, we uncover an intriguing coexistence phase of classical spin liquid and ferroicities, both for dipolar and quadrupolar moments. Additionally, thermal fluctuation drives the system through a nematic Berezinskii-Kosterlitz-Thouless transition, which is accompanied by an anomalous stiffness jump. In the second study, we propose an extended compass model that incorporates subsystem symmetries, allowing for tunable quantum phase transitions. Our findings show that the subsystem symmetries play a dominant role in determining the system's physical properties, giving rise to "fracton-like" spin excitations, a "critical Bose surface" and a nodal-line spin liquid.

References:

[1] Zhidan Li, Chun-Jiong Huang, Changle Liu, Hai-Zhou Lu, Phys. Rev. B 109, 214402 (2024)

[2] Chun-Jiong Huang, Xu-Ping Yao, Gang v. Chen, arXiv:2409.18600 (2024)