Accelerated search for thermoelectric and topological materials using first-principles and machine learning

Abstract

In summary, we have performed first-principles calculations to study the topological phase transitions in chalcopyrite compounds as a function of hydrostatic pressure. These compounds are topological insulators in the native phase with an inverted band order around BZ center. Upon hydrostatic compression, there is a transition from nontrivial TI phase to a Dirac semimetallic state at a critical pressure. Further increase in pressure drives the materials into a trivial semiconductors along with normal ordering of bands. Different quantum phases are characterized by topological invariants as well as surface states. These quantum phase transitions are further validated by model calculations based on L¨uttinger Hamiltonian, which unravels the critical role played by pressure-induced anisotropy of frontier bands in driving the phase transitions. Such a manoeuvre between various topological phases by hydrostatic pressure can stimulate the search for TQPTs in future experiments