Pressure driven topological phase transition in chalcopyrite ZnGeSb2
Abstract
Recently topologically non-trivial phases have been identified in few time-reversal invariant systems that lack of inversion symmetry. Using density functional theory based first-principles calculations, we report a strong topologically non-trivial phase in chalchopyrite ZnGeSb2, which can act as a model system of strained HgTe. The calculations reveal the non-zero topological invariant (Z2), the presence of Dirac cone crossing in the surface spectral functions with spin-momentum locking. We also show that the application of moderate hydrostatic pressure (7 GPa) induces topological phase transition from topological non-trivial phase to a topologically trivial phase. A discontinuity in the tetragonal distortion of non-centrosymmetric ZnGeSb2 plays a crucial role in driving this topological phase transition.