Phys. Rev. B 109, L020202 (2024)
Berezinskii-Kosterlitz-Thouless-like Localization-Localization Transitions in Disordered Two-dimensional Quantized Quadrupole Insulators
C. Wang1,*, Wenxue He1,2, Hechen Ren1,2,3, and X. R. Wang4,5
1 Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin 300350, China
2 Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072, China
3 Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
4 Physics Department, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong
5 HKUST Shenzhen Research Institute, Shenzhen 518057, China
* physcwang@tju.edu.cn
Abstract
Anderson localization transitions are usually referred to as disorder-driven quantum phase transitions from delocalized states to localized states. Here we report an unconventional “Anderson localization transition” in two-dimensional quantized quadrupole insulators. Such transitions are from symmetry-protected topological corner states to disorder-induced normal Anderson localized states, which can occur in the bulk as well as on the boundary. We show that these localization-localization transitions (transitions between two different types of localized states) can happen in both Hermitian and non-Hermitian quantized quadrupole insulators and investigate their criticality by finite-size scaling analysis of the corner density. The scaling analysis suggests that the correlation length of the phase transition, on the Anderson insulator side and near critical disorder Wc, diverges as , a typical feature of Berezinskii-Kosterlitz-Thouless-like transitions.
