Strain-Driven Higher-Order Topological Dirac Semimetal in Noncentrosymmetric γ-GeSe

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Noncentrosymmetric materials are key for exotic quantum states.
• Experimental realization of strain-engineered topological phases remains challenging.

Purpose of the Study:

• To investigate strain-induced topological phase transitions in γ-GeSe.
• To explore the emergence of higher-order topological phases in this material.

Main Methods:

• First-principles calculations were employed.
• Analysis focused on in-plane biaxial tensile strain effects.

Main Results:

• γ-GeSe exhibits sequential topological phase transitions under strain.
• A higher-order topological Dirac semimetal phase was identified.
• This phase features Dirac points and higher-order topological insulating properties.

Conclusions:

• γ-GeSe is a promising material for studying strain-engineered topological phenomena.
• The findings highlight unique topological states in noncentrosymmetric systems.