Spin-rotation symmetry breaking in the superconducting state of CuxBi2Se3
Spin-rotation symmetry breaking in the superconducting state of CuxBi2Se3
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DOI：
10.1038/nphys3781
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发表时间：
2016-09-01
期刊：
影响因子：
19.6
通讯作者：
Zheng, Guo-qing
中科院分区：
文献类型：
--
作者：
Matano, K.;Kriener, M.;Zheng, Guo-qing
自发对称性破缺是理解从基本粒子到物质状态的物理学的一个重要概念。例如，超导态破坏了全球规范对称性，而非传统超导体可能会破坏进一步的对称性。特别是，自旋三重态超导体中的自旋-转动对称性有望被打破。然而，到目前为止，这种对称性破缺的实验证据尚未在任何候选化合物中得到确凿证据。本文利用Se-77核磁共振测量表明，在超导转变温度T-c=3.4K以下，电子掺杂的拓扑绝缘体Cu0.3Bi2Se3的自旋-旋转对称性自发破缺。我们的结果不仅建立了该化合物的自旋三重态超导电性，而且为拓扑超导电性的研究奠定了基础。
Spontaneous symmetry breaking is an important concept for understanding physics ranging from the elementary particles to states of matter. For example, the superconducting state breaks global gauge symmetry, and unconventional superconductors can break further symmetries. In particular, spin-rotational symmetry is expected to be broken in spin triplet superconductors. However, experimental evidence for such symmetry breaking has not been conclusively obtained so far in any candidate compounds. Here, using Se-77 nuclear magnetic resonance measurements, we show that spin-rotation symmetry is spontaneously broken in the hexagonal plane of the electron-doped topological insulator Cu0.3Bi2Se3 below the superconducting transition temperature T-c = 3.4 K. Our results not only establish spin-triplet superconductivity in this compound, but may also serve to lay a foundation for the research of topological superconductivity.