Pressure driven Weyl-topological insulator phase transition in Weyl semimetal SrSi${}_2$

Abstract

Using DFT-based first-principles calculations, we demonstrate the tuning of the electronic structure of Weyl semimetal SrSi${}_2$ via external uniaxial strain. The uniaxial strain facilitates the opening of bandgap along $\Gamma$-X direction and subsequent band inversion between Si $p$ and Sr $d$ orbitals. Z${}_2$ invariants and surface states reveal conclusively that SrSi${}_2$ under uniaxial strain is a strong topological insulator. Hence, uniaxial strain drives the semimetallic SrSi${}_2$ into fully gapped topological insulating state depicting a semimetal to topological insulator phase transition. Our results highlight the suitability of uniaxial strain to gain control over the topological phase transitions and topological states in SrSi${}_2$.

11 pages, 8 figures

References in corpus (8)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• Strain tuning of topological band order in cubic semiconductors
• Strain-induced quantum topological phase transitions in Na3Bi
• Effect of uniaxial stress on the electronic band structure of NbP
• Pressure-Driven Magneto-Topological Phase Transition in a magnetic Weyl semimetal