Robust Room-Temperature Quantum Spin Hall Effect in Methyl-functionalized InBi honeycomb film.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Quantum Computing

Background:

• Two-dimensional (2D) group-III-V honeycomb films are crucial for quantum computing and nanoelectronics.
• High structural stability and large band gaps are essential for realizing quantum spin Hall (QSH) states.

Purpose of the Study:

• To predict and investigate novel 2D III-V materials for QSH effect applications.
• To explore the potential of methyl-functionalized Indium Bismuth (InBiCH3) monolayers.

Main Methods:

• First-principles calculations were employed to study the structural, electronic, and topological properties of InBiCH3.
• Analysis included dynamic stability, band gap, topological invariants (Z2 number), and edge states.

Main Results:

• The InBiCH3 monolayer demonstrates dynamic stability and a significant band gap of 0.29 eV, indicating a QSH state.
• Topological characteristics were confirmed via s-pxy band inversion and time-reversal symmetry-protected helical edge states.
• QSH states are tunable and robust against strain, electric fields, and varying methyl coverage, and persist on h-BN substrates.

Conclusions:

• Methyl-functionalized InBiCH3 is a promising material for spintronic devices due to its robust QSH properties.
• Its large band gap and tunability make it suitable for room-temperature nanoelectronic applications.
• This work highlights the potential of III-V films as a platform for QSH devices.