Superconducting Bi2Te: pressure-induced universality in the (Bi2)m(Bi2Te3)n series

Ryan L. Stillwell; Zsolt Jenei; Samuel T. Weir; Yogesh K. Vohra; Jason R. Jeffries

doi:10.1103/physrevb.93.094511

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arXiv · 1511.02944

Superconducting Bi2Te: pressure-induced universality in the (Bi2)m(Bi2Te3)n series

Ryan L. Stillwell·Zsolt Jenei·Samuel T. Weir·Yogesh K. Vohra·Jason R. Jeffries

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Abstract

Using high-pressure magnetotransport techniques we have discovered superconductivity in Bi2Te, a member of the infinitely adaptive (Bi2)m(Bi2Te3)n series, whose end members, Bi and Bi2Te3, can be tuned to display topological surface states or superconductivity. Bi2Te has a maximum Tc= 8.6 K at P= 14.5 GPa and goes through multiple high pressure phase transitions, ultimately collapsing into a bcc structure that suggests a universal behavior across the series. High-pressure magnetoresistance and Hall measurements suggest a semi-metal to metal transition near 5.4 GPa, which accompanies the hexagonal to intermediate phase transition seen via x-ray diffraction measurements. In addition, the linearity of Hc2(T) exceeds the Werthamer-Helfand-Hohenberg limit, even in the extreme spin-orbit scattering limit, yet is consistent with other strong spin-orbit materials. Considering these results in combination with similar reports on strong spin-orbit scattering materials seen in the literature, we suggest the need for a new theory that can address the unconventional nature of their superconducting states.

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Ryan L. Stillwell, Zsolt Jenei, Samuel T. Weir, Yogesh K. Vohra, Jason R. Jeffries. 2015-11-10. Superconducting Bi2Te: pressure-induced universality in the (Bi2)m(Bi2Te3)n series. https://doi.org/10.1103/physrevb.93.094511

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