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arXiv · 1103.4750

Bulk superconducting phase with a full energy gap in the doped topological insulator Cu_xBi_2Se_3

M. Kriener·Kouji Segawa·Zhi Ren·Satoshi Sasaki·Yoichi Ando
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Abstract

The superconductivity recently found in the doped topological insulator Cu_xBi_2Se_3 offers a great opportunity to search for a topological superconductor. We have successfully prepared a single-crystal sample with a large shielding fraction and measured the specific-heat anomaly associated with the superconductivity. The temperature dependence of the specific heat suggests a fully-gapped, strong-coupling superconducting state, but the BCS theory is not in full agreement with the data, which hints at a possible unconventional pairing in Cu_xBi_2Se_3. Also, the evaluated effective mass of 2.6m_e (m_e is the free electron mass) points to a large mass enhancement in this material.

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M. Kriener, Kouji Segawa, Zhi Ren, Satoshi Sasaki, Yoichi Ando. 2011-03-24. Bulk superconducting phase with a full energy gap in the doped topological insulator Cu_xBi_2Se_3. https://doi.org/10.1103/physrevlett.106.127004

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