Topological Superconductivity in CuxBi2Se3
Topological Superconductivity in CuxBi2Se3
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DOI：
10.1103/physrevlett.107.217001
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发表时间：
2011-11-14
影响因子：
8.6
通讯作者：
Ando, Yoichi
中科院分区：
文献类型：
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作者：
Sasaki, Satoshi;Kriener, M.;Ando, Yoichi
拓扑超导体（TSC）具有拓扑保护的无间隙表面态，其本质上是由马约拉纳费米子组成的Andreev束缚态。虽然TSC尚未被发现，但已经预测掺杂的拓扑绝缘体CuxBi2Se3具有类似于3k以下的超导性，具有拓扑超导状态。我们报道了超导CuxBi2Se3的劈裂表面的点接触光谱存在一个零偏导峰（ZBCP），这意味着非常规的超导性。对所有可能超导态的理论考虑帮助我们得出结论，该ZBCP是由马约拉纳费米子引起的，并为CuxBi2Se3的拓扑超导性提供了证据。此外，我们还发现了一个不寻常的赝隙，它在接近20k的温度下发展，并与拓扑超导态共存。
A topological superconductor (TSC) is characterized by the topologically protected gapless surface state that is essentially an Andreev bound state consisting of Majorana fermions. While a TSC has not yet been discovered, the doped topological insulator CuxBi2Se3, which superconducts below similar to 3 K, has been predicted to possess a topological superconducting state. We report that the point-contact spectra on the cleaved surface of superconducting CuxBi2Se3 present a zero-bias conductance peak (ZBCP) which signifies unconventional superconductivity. Theoretical considerations of all possible superconducting states help us conclude that this ZBCP is due to Majorana fermions and gives evidence for a topological superconductivity in CuxBi2Se3. In addition, we found an unusual pseudogap that develops below similar to 20 K and coexists with the topological superconducting state.