论文标题
揭示了Fe- chalcogenide超导体FETE1-XSEX中时间反转对称性破坏的起源
Revealing the Origin of Time-reversal Symmetry Breaking in Fe-chalcogenide Superconductor FeTe1-xSex
论文作者
论文摘要
最近有证据表明，用于时间反转对称性破坏（TRSB）的拓扑超导体Fe-Chalcogenide Fete1-XSEX，其性质对在该系统中发现的Majorana零模式（MZM）具有很强的意义。但是，尚不清楚TRSB是驻留在拓扑表面状态（TSS）还是散装状态，以及是由于非常规的TRSB超导顺序参数还是相互缠绕的顺序。在这里，通过使用Sagnac干涉仪和大量的磁敏感性测量测量，在超导FETE1-XSEX晶体中进行表面磁通效应（烟雾）测量，我们还将TRSB定位于TSS，在那里我们还检测到了DIRAC间隙。此外，我们观察到了名义上相同组成的非渗透性FETE1-XSEX中的表面TRSB，表明TRSB来自互换的表面铁磁（FM）顺序。观察到的表面FM熊与在2D Van der Waals晶体中发现的二维（2D）FM相似，并且对确切的化学成分高度敏感，从而提供了一种用于优化可用于稳健量子计算的Majorana颗粒条件的方法。
Recently evidence has emerged in the topological superconductor Fe-chalcogenide FeTe1-xSex for time-reversal symmetry breaking (TRSB), the nature of which has strong implications on the Majorana zero modes (MZM) discovered in this system. It remains unclear however whether the TRSB resides in the topological surface state (TSS) or in the bulk, and whether it is due to an unconventional TRSB superconducting order parameter or an intertwined order. Here by performing in superconducting FeTe1-xSex crystals both surface-magneto-optic-Kerr effect (SMOKE) measurements using a Sagnac interferometer and bulk magnetic susceptibility measurements, we pinpoint the TRSB to the TSS, where we also detect a Dirac gap. Further, we observe surface TRSB in non-superconducting FeTe1-xSex of nominally identical composition, indicating that TRSB arises from an intertwined surface ferromagnetic (FM) order. The observed surface FM bears striking similarities to the two-dimensional (2D) FM found in 2D van der Waals crystals, and is highly sensitive to the exact chemical composition, thereby providing a means for optimizing the conditions for Majorana particles that are useful for robust quantum computing.
