Nuclear magnetic relaxation rates of unconventional superconductivity in doped topological insulators
Nuclear magnetic relaxation rates of unconventional superconductivity in doped topological insulators
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DOI：
10.1103/physrevb.94.134516
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发表时间：
2016-05
影响因子：
3.7
通讯作者：
Y. Nagai;Y. Ota
中科院分区：
文献类型：
--
作者：
Y. Nagai;Y. Ota
研究了掺杂拓扑绝缘体M（= Cu，Nb，Sr）x Bi 2 Se 3和Sn 1-x In x Te中的核磁弛豫率随温度的变化关系，并利用该关系检测了拓扑超导性的信号.临界温度Tc以下的Hebel-Slichter相干效应依赖于掺杂拓扑绝缘体的最小模型预测的超导态。在类似于$^{3}$He中的ABM相的节点各向异性拓扑状态中，NMR速率在Tc以下具有常规的$s$波状相干峰。相比之下，在完全带隙的各向同性拓扑超导状态下，低于Tc的速率呈现出反峰轮廓。此外，在二重面内各向异性拓扑超导态中，没有相干效应，这与手征p$波态相似。因此，我们揭示了NMR速率揭示了掺杂拓扑绝缘体的非常规超导性。
We study the temperature dependence of nuclear magnetic relaxation (NMR) rates to detect a sign of topological superconductivity in doped topological insulators, such as $M$($=$Cu,Nb,Sr)$_{x}$Bi$_{2}$Se$_{3}$ and Sn$_{1-x}$In$_{x}$Te. The Hebel-Slichter coherence effect below a critical temperature Tc depends on the superconducting states predicted by a minimal model of doped topological insulators. In a nodal anisotropic topological state similar to the ABM-phase in $^{3}$He, the NMR rate has a conventional $s$-wave like coherence peak below Tc. In contrast, in a fully-gapped isotropic topological superconducting state, this rate below Tc exhibits an anti-peak profile. Moreover, in a two-fold in-plane anisotropic topological superconducting state, there is no coherence effect, which is similar to that in a chiral $p$-wave state. Thus, we reveal that the NMR rates shed light on unconventional superconductivity in doped topological insulators.