Theoretical study of impurity and correlation effects on topological insulators

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540338
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: FURUSAKI Akira 独立行政法人理化学研究所, 古崎物性理論研究室, 主任研究員 (10238678)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: トポロジカル絶縁体 / トポロジカル超伝導 / ディラック電子 / アンダーソン局在

Outline of Final Research Achievements

The classification of topological insulators and superconductors is reformulated as classification of Dirac mass terms, and a theoretical framework is developed for finding the classification from the topology of classifying spaces obtained from the extension problem of Clifford algebras which are generated from Dirac Hamiltonians and symmetry transformation operators. Applying this theoretical framework led to the following results: it was shown that surface states of weak Z2 topological insulators/superconductors are stable against disorder; phase diagrams for the Anderson localization problem of disordered topological insulators/superconductors are obtained; the classification of Weyl/Dirac semimetals with Z2 topological charge is achieved. Furthermore, a model of SU(3) spins is constructed which has a symmetry protected topological ground state.

Free Research Field

物性理論