Simultaneous low-temperature electrical resistivity and Hall effect measurements were performed on single-crystalline Bi2Se3 under applied pressures up to 50 GPa. As a function of pressure, superconductivity is observed to onset above 11 GPa with a transition temperature Tc and upper critical field Hc2 that both increase with pressure up to 30 GPa, where they reach maximum values of 7 K and 4 T, respectively. Upon further pressure increase, Tc remains anomalously constant up to the highest achieved pressure. Conversely, the carrier concentration increases continuously with pressure, including a tenfold increase over the pressure range where Tc remains constant. Together with a quasi-linear temperature dependence of Hc2 that exceeds the orbital and Pauli limits, the anomalously stagnant pressure dependence of Tc points to an unconventional pressure-induced pairing state in Bi2Se3 that is unique among the superconducting topological insulators.
@article{arxiv.1302.6488,
title = {Pressure-Induced Unconventional Superconducting Phase in the Topological Insulator Bi2Se3},
author = {K. Kirshenbaum and P. S. Syers and A. P. Hope and N. P. Butch and J. R. Jeffries and S. T. Weir and J. J. Hamlin and M. B. Maple and Y. K. Vohra and J. Paglione},
journal= {arXiv preprint arXiv:1302.6488},
year = {2013}
}
Comments
8 pages with Supplemental Material, to appear in Phys. Rev. Lett