A topological superconductor A promising path toward topological quantum computing involves exotic quasiparticles called the Majorana bound states (MBSs). MBSs have been observed in heterostructures that require careful nanofabrication, but the complexity of such systems makes further progress tricky. Zhang et al. identified a topological superconductor in which MBSs may be observed in a simpler way by looking into the cores of vortices induced by an external magnetic field. Using angle-resolved photoemission, the researchers found that the surface of the iron superconductor FeTe0.55Se0.45 satisfies the required conditions for topological superconductivity. Science, this issue p. 182 Angle-resolved photoemission spectroscopy indicates that FeTe0.55Se0.45 harbors Dirac-cone–type spin-helical surface states. Topological superconductors are predicted to host exotic Majorana states that obey non-Abelian statistics and can be used to implement a topological quantum computer. Most of the proposed topological superconductors are realized in difficult-to-fabricate heterostructures at very low temperatures. By using high-resolution spin-resolved and angle-resolved photoelectron spectroscopy, we find that the iron-based superconductor FeTe1–xSex (x = 0.45; superconducting transition temperature Tc = 14.5 kelvin) hosts Dirac-cone–type spin-helical surface states at the Fermi level; the surface states exhibit an s-wave superconducting gap below Tc. Our study shows that the surface states of FeTe0.55Se0.45 are topologically superconducting, providing a simple and possibly high-temperature platform for realizing Majorana states.

中文翻译：

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铁基超导体表面拓扑超导性的观察

拓扑超导体 拓扑量子计算的一条有前途的途径涉及称为马约拉纳束缚态 (MBS) 的奇异准粒子。已经在需要仔细纳米制造的异质结构中观察到 MBS，但此类系统的复杂性使得进一步的进展变得棘手。张等人。确定了一种拓扑超导体，其中 MBS 可以通过观察外部磁场引起的漩涡核心以更简单的方式观察到。研究人员使用角分辨光电子发射，发现铁超导体 FeTe0.55Se0.45 的表面满足拓扑超导所需的条件。科学，这个问题 p。182 角分辨光电子能谱表明 FeTe0.55Se0.45 具有狄拉克锥型自旋螺旋表面态。预计拓扑超导体将承载遵守非阿贝尔统计的奇异马约拉纳态，可用于实现拓扑量子计算机。大多数提出的拓扑超导体是在非常低的温度下以难以制造的异质结构实现的。通过使用高分辨率自旋分辨和角度分辨光电子能谱，我们发现铁基超导体 FeTe1-xSex（x = 0.45；超导转变温度 Tc = 14.5 开尔文）承载狄拉克锥型自旋螺旋表面态在费米能级；表面态表现出低于 Tc 的 s 波超导间隙。我们的研究表明，FeTe0.55Se0.45 的表面态是拓扑超导的，为实现马约拉纳态提供了一个简单且可能的高温平台。