Measuring the Boundary Gapless State and Criticality via Disorder Operator
Abstract
The disorder operator is often designed to reveal the conformal field theory information in quantum many-body systems. By using large-scale quantum Monte Carlo simulation, we study the scaling behavior of disorder operators on the boundary in the two-dimensional Heisenberg model on the square-octagon lattice with gapless topological edge state. In the Affleck-Kennedy-Lieb-Tasaki phase, the disorder operator is shown to hold the perimeter scaling with a logarithmic term associated with the Luttinger liquid parameter K. This effective Luttinger liquid parameter K reflects the low-energy physics and CFT for (1+1)D boundary. At bulk critical point, the effective K is suppressed but keeps finite value, indicating the coupling between the gapless edge state and bulk fluctuation. The logarithmic term numerically captures this coupling picture, which reveals the (1+1)D SU(2)1 CFT and (2+1)D O(3) CFT at boundary criticality. Our Letter paves a new way to study the exotic boundary state and boundary criticality.
Cite
@article{arxiv.2311.05690,
title = {Measuring the Boundary Gapless State and Criticality via Disorder Operator},
author = {Zenan Liu and Rui-Zhen Huang and Yan-Cheng Wang and Zheng Yan and Dao-Xin Yao},
journal= {arXiv preprint arXiv:2311.05690},
year = {2024}
}
Comments
8 Pages,7 figures