Classification of interacting electronic topological insulators in three dimensions

Area of Science:

• Condensed-matter physics
• Topological phases of matter
• Strongly correlated electron systems

Background:

• Understanding topological insulators is crucial for quantum technologies.
• The interplay of electron interactions and topology remains a key challenge.
• Existing classifications often neglect strong interaction effects.

Purpose of the Study:

• To investigate topological insulators in the presence of strong electron interactions.
• To identify and classify all possible interacting topological phases.
• To explore the relationship between interacting and noninteracting topological insulators.

Main Methods:

• Theoretical classification of topological phases.
• Analysis of symmetry-breaking and interaction effects.
• Identification of novel Mott insulator states.

Main Results:

• Discovered six new interacting topological insulators lacking noninteracting counterparts.
• Established a complete list of eight topologically distinct phases.
• Characterized two phases as topological paramagnets (Mott insulators with spin analogs).

Conclusions:

• Strong electron interactions significantly expand the landscape of topological insulators.
• The identified eight phases provide a comprehensive framework for understanding interacting topological matter.
• Experimental signatures for these novel phases were discussed, paving the way for future research.