Pressure effects on crystal and electronic structure of bismuth tellurohalides

Abstract

We study the possibility of pressure-induced transitions from a normal semiconductor to a topological insulator (TI) in bismuth tellurohalides using density functional theory and tight-binding method. In BiTeI this transition is realized through the formation of an intermediate phase, a Weyl semimetal, that leads to modification of surface state dispersions. In the topologically trivial phase, the surface states exhibit a Bychkov-Rashba type dispersion. The Weyl semimetal phase exists in a narrow pressure interval of 0.2 GPa. After the Weyl semimetal--TI transition occurs, the surface electronic structure is characterized by gapless states with linear dispersion. The peculiarities of the surface states modification under pressure depend on the band-bending effect. We have also calculated the frequencies of Raman active modes for BiTeI in the proposed high-pressure crystal phases in order to compare them with available experimental data. Unlike BiTeI, in BiTeBr and BiTeCl the topological phase transition does not occur. In BiTeBr, the crystal structure changes with pressure but the phase remains a trivial one. However, the transition appears to be possible if the low-pressure crystal structure is retained. In BiTeCl under pressure, the topological phase does not appear up to 18 GPa due to a relatively large band gap width in this compound.

References in corpus (7)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Emergent quantum confinement at topological insulator surfaces
• Weyl semimetals from noncentrosymmetric topological insulators
• Strongly spin-orbit coupled two-dimensional electron gas emerging near the surface of polar semiconductors
• Full electrical control of Charge and Spin conductance through Interferometry of Edge States in Topological Insulators

Cited by in corpus (7)

• Electrically Controlled Spin Injection from Giant Rashba Spin-Orbit Conductor BiTeBr
• Temperature dependence of the bulk Rashba splitting in the bismuth tellurohalides
• Temperature dependence of the topological phase transition of BiTeI from first principles
• Interlayer RKKY Coupling in Bulk Rashba Semiconductors under Topological Phase Transition
• 2D and 3D topological phases in BiTe$X$ compounds
• BiTeCl and BiTeBr: a comparative high-pressure optical study
• Combining graph deep learning and London dispersion interatomic potentials: A case study on pnictogen chalcohalides