Superconductivity in the Narrow-Gap Semiconductor CsBi_4Te_6

摘要

Superconductivity was discovered in the narrow-gap semiconductor CsBi_4Te_6. A superconducting transition around 4.4 K was observed for p-type samples in temperature-dependent resistivity and magnetic susceptibility data. Stoichiometric CsBi_4Te_6 is not a superconductor. A remarkably high critical field of ~10 T was estimated from the field-dependent resistivity data. The strongly anisotropic CsBi_4Te_6 system is monoclinic and the first member of a larger homologous series Cs_4[Bi_(2n+4)Te_(3n+6)] that exhibits unconventional superconductivity, suggesting that proper doping of the homologous series may create a novel class of superconductors from semiconductors.