Topological Phase Transition in Sb₂Mg₃ Assisted by Strain.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Topological insulators possess unique dissipationless surface states.
• These materials hold promise for next-generation spintronic applications.
• Understanding phase transitions is crucial for material design.

Purpose of the Study:

• To investigate the potential of Sb₂Mg₃ as a topological material.
• To explore the effects of tensile strain on the electronic properties of Sb₂Mg₃.
• To identify conditions for achieving a topological phase transition.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Tensile strain was systematically applied to Sb₂Mg₃.
• Electronic band structure and spin-orbital coupling (SOC) effects were analyzed.

Main Results:

• Sb₂Mg₃ transitions from a normal insulator to a topological insulator under tensile strain (ε = 7.2%).
• A nontrivial topological band gap of 0.22 eV is opened due to SOC.
• The topological invariant (Z₂ = 1) confirms the nontrivial phase.
• An orbital-filtering effect was observed, leading to spin saturation.

Conclusions:

• Tensile strain can induce a topological phase transition in Sb₂Mg₃.
• This material exhibits tunable topological properties relevant for spintronics.
• The findings expand the landscape of topological insulators for device applications.