Temperature Dependent n-p Transition of 3 Dimensional Dirac Semimetal Na${}_3$Bi Thin Film

Abstract

We study the temperature dependence ($77$ K - $475$ K) of the longitudinal resistivity and Hall coefficient of thin films (thickness $20$ nm) of three dimensional topological Dirac semimetal Na${}_3$Bi grown via molecular beam epitaxy (MBE). The temperature-dependent Hall coefficient is electron-like at low temperature, but transitions to hole-like transport around $200$ K. We develop a model of a Dirac band with electron-hole asymmetry in Fermi velocity and mobility (assumed proportional to the square of Fermi velocity) which explains well the magnitude and temperature dependence of the Hall resistivity. We find that the hole mobility is about $7$ times larger than the electron mobility. In addition, we find that the electron mobility decreases significantly with increasing temperature, suggesting electron-phonon scattering strongly limits the room temperature mobility.

12 pages

References in corpus (6)

• A self-consistent theory for graphene transport
• Carrier screening, transport, and relaxation in 3D Dirac semimetals
• Intrinsic Electron-Phonon Resistivity in Bi2Se3 in the Topological Regime
• Coulomb disorder in three-dimensional Dirac systems
• Robust Dual Topological Character with Spin-Valley Polarization in a Monolayer of the Dirac Semimetal Na${}_3$Bi
• Electrostatic Modulation of the Electronic Properties of Dirac Semimetal Na3Bi