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Updated: Jul 19, 2025
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Published on: July 29, 2013
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Anisotropic Topological Anderson Transitions in Chiral Symmetry Classes
Zhenyu Xiao1, Kohei Kawabata2,3, Xunlong Luo4
1International Center for Quantum Materials, Peking University, Beijing 100871, China.
Physical Review Letters
|August 18, 2023
Summary
Disordered systems with a weak topological index exhibit a novel quasilocalized phase. This topological Anderson transition reveals new universality classes in quantum phase transitions.
Area of Science:
- Condensed Matter Physics
- Topological Matter Physics
- Quantum Phase Transitions
Background:
- Disordered systems exhibit Anderson localization, a phenomenon where wave functions decay exponentially.
- Topological insulators and semimetals possess unique electronic properties protected by topology.
- Chiral classes (AIII and BDI) describe specific symmetries relevant to topological phases.
Purpose of the Study:
- To investigate quantum phase transitions in three-dimensional disordered systems within chiral classes.
- To explore the impact of weak topological indices on system behavior.
- To identify and characterize emergent phases and their associated critical phenomena.
Main Methods:
- Numerical simulations of three-dimensional disordered systems.
- Analysis of systems with and without weak topological indices.
- Calculation of critical exponents for Anderson transitions.
Main Results:
- Discovery of a 'quasilocalized' phase in systems with nontrivial weak topological indices.
- Wave functions in the quasilocalized phase are delocalized in one direction and localized in others.
- Critical exponents differ from systems without weak topological indices, indicating new universality classes.
- Anisotropic transport phenomena observed in disordered weak topological insulators and nodal-line semimetals.
Conclusions:
- Weak topological indices induce novel universality classes in quantum phase transitions.
- The quasilocalized phase and topological Anderson transition have observable consequences in transport properties.
- These findings are relevant for understanding disordered topological materials like weak topological insulators and nodal-line semimetals.
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