High pressure transport properties of the topological insulator Bi₂Se₃

Abstract

We report x-ray diffraction, electrical resistivity, and magnetoresistance measurements on Bi2Se3 under high pressure and low temperature conditions. Pressure induces profound changes in both the room temperature value of the electrical resistivity as well as the temperature dependence of the resistivity. Initially, pressure drives Bi2Se3 toward increasingly insulating behavior and then, at higher pressures, the sample appears to enter a fully metallic state coincident with a change in the crystal structure. Within the low pressure phase, Bi2Se3 exhibits an unusual field dependence of the transverse magnetoresistance Δρ(xx) that is positive at low fields and becomes negative at higher fields. Our results demonstrate that pressures below 8 GPa provide a non-chemical means to controllably reduce the bulk conductivity of Bi2Se3.

Triplet superconductivity in 3D Dirac semi-metal due to exchange interaction

“…In these materials there are at least two bands of opposite chiralities. Such a band structure appear in many recently studied materials including copper doped TI Bi 2 Se 3 in which the triplet superconductivity is suspected 18 . In the framework of the "conventional" phonon mediated local attraction model we classified, under simplifying assumptions of the 3D rotation invariance, inversion and the time reversal, possible pairing channels.…”

Growth and characterization of Bi2Se3 crystals by chemical vapor transport

“…We note a very recent high-pressure transport property study on the Bi 2 Se 3 crystals by the Bridgman method. 27 It was shown that pressure drove Bi 2 Se 3 towards insulating behavior for P < 7 GPa through a sharp decrease in mobility. So, our similar LRT behavior may be of the same origin.…”

Trapping of three-dimensional electrons and transition to two-dimensional transport in the three-dimensional topological insulator Bi2Se3under high pressure

“…In this paper we explore the possibility of isolating the 2D electron contribution to charge transport by applying hydrostatic pressure, based on the observed increase of Bi 2 Se 3 bandgap under pressure, which could result in a reduction of the 3D electron mobility or in 3D electrons being trapped by pressure-induced deep levels. During the preparation of the revised version of this paper, the same strategy was used by Hamlin et al [22], showing that the resistivity of Bi 2 Se 3 samples with electrons concentrations of the order of 10 19 cm -3 increases in fact under pressure by nearly one order of magnitude up to 8 GPa. In this paper we investigate the transport and optical properties of Bi 2 Se 3 under hydrostatic pressure and correlate them to pressure induced changes in its electronic structure, as calculated by means of ab-initio methods.…”