Electron–Hole Scattering Limited Transport of Dirac Fermions in a Topological Insulator

We experimentally investigate the effect of electron temperature on transport in two-dimensional Dirac surface states three-dimensional topological insulator HgTe. find that around minimal conductivity point, where both electrons and holes are present, heating carriers with a DC current results non-monotonic differential resistance narrow channels. show observed initial increase can be attributed to electron-hole scattering, while decrease follows naturally from change Fermi energy charge carriers. Both effects governed dominantly by van Hove singularity bulk valence band. The demonstrate importance interband scattering properties insulators.