Band splitting in bilayer stanene electronic structure scrutinized via first principle DFT calculations

TL;DR

This study uses first-principles DFT calculations to analyze how stacking order and angle in bilayer stanene influence its electronic structure, revealing band splitting and valley-dependent spin polarization.

Contribution

It is the first detailed investigation of stacking angle effects on bilayer stanene's electronic properties using DFT, highlighting band splitting and spin polarization phenomena.

Findings

Band splitting due to SOC observed in bilayer stanene.

Stacking angle and order significantly affect electronic states.

Distinct spin-up and spin-down channels emerge from band splitting.

Abstract

The recent work on stanene as quantum spin Hall insulators made us investigate bilayer stanene using first principle calculations. With an aim of improving and developing new properties, via modulating the stacking order (and angle) of the bilayers. This stacking of layers has been proven technique for modulating the properties of monolayer materials. Here we design multiple bilayer systems, with different stacking angles and AA and AB configurations. Rather observing an improvement in bandgap due to spin-orbit coupling (SOC), we witness a splitting of the band due to SOC, a characteristic behavior of stacked MoS2 sheets. This splitting of the bands gives rise to different, independent and distinct spin-up and spin-down channels, manifesting a valley dependent spin polarization. Also, as a contrast to stacked MoS2 system we notice in our system the stacking angle and order, does effect electronic states.