Phase diagram of a pressure-induced superconducting state and its relation to the Hall coefficient of Bi${}_2$Te${}_3$ single crystals

Pressure-induced superconductivity and its relation to the corresponding Hall coefficient ($R_H$) have been investigated for Bi${}_2$Te${}_3$, a known topological insulator, through in situ measurements of magnetoresistance and ac susceptibility with diamond anvil cells. A full phase diagram is presented which shows a complex dependence of the superconducting transition temperature as a function of pressure over an extensive range. High-pressure $R_H$ measurements reveal a close relation to these complex behaviors; in particular, an abrupt change of ${\mathit{dR}}_H/d$$P$ is observed in crossing from the nonsuperconducting to the superconducting ambient-pressure phase.

Figure 1

Electrical resistance of Bi${}_2$Te${}_3$ as a function of temperature at different pressures.

Figure 2

(a) Magnetic-field dependence of the resistive drop of Bi${}_2$Te${}_3$ under different magnetic fields of (a) 4.8 and (b) 13.6 GPa. The real part of the ac susceptibility of the sample at 5.8 GPa is shown in (c). The $T_c$ dependence of the magnetic field is displayed in (d).

Figure 3

(a) Pressure dependence of superconducting transition temperature in three different phases of Bi${}_2$Te${}_3$ crystal structure. (b) Corresponding pressure dependence of Hall coefficient $R_H$. The lines are guides to the eye.