Dynamically Stable Topological Phase of Arsenene.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Arsenene, a 2D material, exhibits unique electronic properties.
• Strain engineering is a key method for tuning material characteristics.
• Understanding topological phase transitions is vital for novel electronic applications.

Purpose of the Study:

• To investigate the electronic structure and topological phase transition of arsenene under strain.
• To determine the stability and properties of strained arsenene.
• To explore arsenene as a potential candidate for nanoelectronic devices.

Main Methods:

• First-principles calculations using density functional theory (DFT).
• Analysis of phonon band structures to assess dynamic stability.
• Investigation of electronic band structures, including the effects of spin-orbit coupling (SOC).
• Calculation of Z2 topological invariant to identify topological phases.

Main Results:

• Arsenene's buckling is strain-dependent.
• Dynamical stability is maintained up to 18% tensile strain.
• A direct bandgap closes at 13% tensile strain, leading to band inversion.
• A topological insulator phase is achieved at 14% strain with SOC, featuring a 43 meV bandgap.
• The Z2 topological invariant confirms the topological insulator phase (ν=1).

Conclusions:

• Strained arsenene exhibits tunable electronic properties and can undergo a topological phase transition.
• The dynamically stable topological phase of arsenene makes it a promising material for nanoelectronic applications.
• Spin-orbit coupling plays a critical role in inducing the topological insulating state in arsenene.