Phonon Transport in Defect-Laden Bilayer Janus PtSTe Studied Using Neural-Network Force Fields

We explore the phonon transport properties of defect-laden
bilayer
PtSTe using equilibrium molecular dynamics simulations based on a
neural-network force field. Defects prove very efficient at depressing
the thermal conductivity of the structure, and flower defects have
a particularly powerful effect, comparable to that of double vacancies.
Furthermore, the conductivity of the structure with flower defects
exhibits an unusual temperature dependence due to structural instability
at high temperatures. We look into the distortion to normal modes
around the defect by means of the projected phonon density of states
and find diverse phenomena including localized modes and blue shifts.