Quasiparticle interference and symmetry of superconducting order parameter in strongly electron-doped iron-based superconductors
Quasiparticle interference and symmetry of superconducting order parameter in strongly electron-doped iron-based superconductors
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DOI：
10.1088/1367-2630/ab2a82
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发表时间：
2019-03
影响因子：
3.3
通讯作者：
J. Böker;P. Volkov;P. Hirschfeld;I. Eremin
中科院分区：
文献类型：
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作者：
J. Böker;P. Volkov;P. Hirschfeld;I. Eremin
最近的实验报告中的显着的自旋轨道耦合（SOC）和一个符号变化的有序参数的Li 1 −xFex（OHFe）1−yZnySe超导体中只有电子口袋存在的动机，我们研究可能的库珀配对对称性和它们的准粒子干涉（QPI）签名。我们发现，每个产生的状态-s-波，d-波和螺旋p-波-可以有一个完整的间隙密度的状态与角分辨光电子能谱实验一致，由于SOC，是一个混合物的自旋单线态和三线态成分导致内和带间的功能在QPI信号。通过对QPI模型的分析，我们发现只有自旋三重态主导的偶宇称A1 g（s波）和B2 g（d波）配对态与实验结果一致。此外，我们表明，这些国家确实可以实现在一个微观模型与类原子的相互作用，并研究其可能的签名自旋分辨STM实验。
Motivated by recent experimental reports of significant spin–orbit coupling (SOC) and a sign-changing order-parameter in the Li1−xFex(OHFe)1−yZnySe superconductor with only electron pockets present, we study the possible Cooper-pairing symmetries and their quasiparticle interference (QPI) signatures. We find that each of the resulting states—s-wave, d-wave and helical p-wave—can have a fully gapped density of states consistent with angle-resolved photoemission spectroscopy experiments and, due to SOC, are a mixture of spin singlet and triplet components leading to intra- and inter-band features in the QPI signal. Analyzing predicted QPI patterns we find that only the spin-triplet dominated even parity A1g (s-wave) and B2g (d-wave) pairing states are consistent with the experimental data. Additionally, we show that these states can indeed be realized in a microscopic model with atomic-like interactions and study their possible signatures in spin-resolved STM experiments.