Tuning the Fermi level through the Dirac point of giant Rashba semiconductor BiTeI with pressure

Abstract

We report measurements of Shubnikov-de Haas oscillations in the giant Rashba semiconductor BiTeI under applied pressures up to $\sim 2\mathrm{GPa}$. We observe one high frequency oscillation at all pressures and one low frequency oscillation that emerges between $\sim 0.3-0.7\mathrm{GPa}$ indicating the appearance of a second small Fermi surface. BiTeI has a conduction band bottom that is split into two sub-bands due to the strong Rashba coupling, resulting in a `Dirac point'. Our results suggest that the chemical potential starts below the Dirac point in the conduction band at ambient pressure and moves upward, crossing it as pressure is increased. The presence of the chemical potential above this Dirac point results in two Fermi surfaces. We present a simple model that captures this effect and can be used to understand the pressure dependence of our sample parameters. These extracted parameters are in quantitative agreement with first-principles calculations and other experiments. The parameters extracted via our model support the notion that pressure brings the system closer to the predicted topological quantum phase transition.

15 pages, 5 figures

References in corpus (2)

• Strong spin-orbit splitting on Bi surfaces
• Rashba type spin-orbit splitting of quantum well states in ultrathin Pb films

Cited by in corpus (6)

• Observation of topological transition of Fermi surface from a spindle-torus to a torus in large bulk Rashba spin-split BiTeCl
• Collective modes in two- and three-dimensional electron systems with Rashba spin-orbit coupling
• Bulk Signatures of Pressure-Induced Band Inversion and Topological Phase Transitions in Pb${}_{1-x}$Sn${}_x$Se
• Temperature dependence of the topological phase transition of BiTeI from first principles
• Spin-orbit interaction enabled electronic Raman scattering from charge collective modes
• Nb-substitution suppresses the superconducting critical temperature of pressurized MoB${}_2$