Chern insulators from heavy atoms on magnetic substrates

Area of Science:

• Condensed matter physics
• Materials science
• Quantum materials

Background:

• Chern insulators are topological materials with potential applications in quantum computing and spintronics.
• Discovering new Chern insulators is crucial for advancing these fields.
• Existing methods for finding Chern insulators are limited.

Purpose of the Study:

• To propose and verify a novel search strategy for identifying Chern insulators.
• To explore the potential of combining elements with large spin-orbit coupling and magnetic insulators.
• To computationally identify candidate Chern insulator materials.

Main Methods:

• Proposing a theoretical framework for searching Chern insulators.
• Utilizing first-principles calculations to compute Chern numbers and anomalous Hall conductivity.
• Investigating systems formed by depositing atomic layers (e.g., Bismuth) on magnetic insulator surfaces (e.g., MnTe, MnSe, EuS).

Main Results:

• Demonstrated that depositing elements with large spin-orbit coupling on magnetic insulators can create isolated surface bands with nonzero Chern numbers.
• Identified several candidate Chern insulator systems.
• Calculated significant energy gaps (up to 140 meV) in promising candidate materials.

Conclusions:

• The proposed search strategy is effective in identifying potential Chern insulators.
• The studied material systems show promise for realizing Chern insulator states.
• This work paves the way for the experimental discovery of new Chern insulators.