Quantum phase transitions in Sn bilayer based interfacial systems by an external strain.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Understanding the electronic properties of 2D materials like stanene is crucial for next-generation electronics.
• Interface effects and strain engineering are key strategies for tuning material properties.
• Stanene's topological properties and potential for spintronic applications are of significant interest.

Purpose of the Study:

• To investigate the impact of interface polarization and strain on the electronic structure of bilayer stanene.
• To explore the formation of Dirac cone states in stanene/antimony(bismuth) and stanene/antimony2telluride systems.
• To provide theoretical insights into manipulating topological states for spintronic device applications.

Main Methods:

• First-principle calculations were employed to simulate and analyze the electronic structures.
• The study considered stanene bilayers on bilayer antimony(bismuth) and quintuple layer antimony2telluride substrates.
• A tight-binding lattice model was used to explain the emergence of Dirac cones under tensile strain.

Main Results:

• Interface polarization and strain significantly alter stanene's electronic structure and configuration (low-buckled vs. high-buckled).
• Strained stanene/antimony(bismuth) systems do not exhibit Dirac cone states in the band gap.
• Strained stanene/antimony2telluride systems show the emergence of spin-polarized Dirac cone states within the band gap.

Conclusions:

• Tensile strain can effectively introduce spin-polarized Dirac cones at the K point in stanene/antimony2telluride interfaces.
• The findings suggest the feasibility of inducing quantum phase transitions in stanene thin films.
• This research offers a pathway for designing atomically thin spintronic devices by controlling interfacial and strain effects.