A possible propagating Majorana Majorana states in solid-state systems may one day form a basis for topological quantum computing. Most of the candidates identified so far have been Majorana bound states, but theorists have predicted that propagating Majorana states may exist as well. Wang et al. looked for such a state on the surface of the material FeSe0.45Te0.55 (see the Perspective by Tewari and Stanescu). Using scanning tunneling spectroscopy, the researchers measured a flat, bias-independent density of states along a particular type of domain wall, which was consistent with a theoretical prediction for a propagating Majorana state in this material. Although topologically trivial origins of this finding are difficult to completely rule out, the work is likely to stimulate interest in iron-based superconductors as hosts of Majorana states. Science, this issue p. 104; see also p. 23 Scanning tunneling spectroscopy suggests a propagating Majorana state along a domain wall on the surface of FeSe0.45Te0.55. The possible realization of Majorana fermions as quasiparticle excitations in condensed-matter physics has created much excitement. Most studies have focused on Majorana bound states; however, propagating Majorana states with linear dispersion have also been predicted. Here, we report scanning tunneling spectroscopic measurements of crystalline domain walls (DWs) in FeSe0.45Te0.55. We located DWs across which the lattice structure shifts by half a unit cell. These DWs have a finite, flat density of states inside the superconducting gap, which is a hallmark of linearly dispersing modes in one dimension. This signature is absent in DWs in the related superconductor, FeSe, which is not in the topological phase. Our combined data are consistent with the observation of dispersing Majorana states at a π-phase shift DW in a proximitized topological material.

中文翻译：

---

在铁基超导体中分散一维马约拉纳通道的证据

一种可能在固态系统中传播的 Majorana Majorana 状态有朝一日可能会成为拓扑量子计算的基础。迄今为止确定的大多数候选状态都是马约拉纳束缚态，但理论家预测也可能存在传播马约拉纳态。王等人。在材料 FeSe0.45Te0.55 的表面上寻找这种状态（参见 Tewari 和 Stanescu 的观点）。使用扫描隧道光谱，研究人员测量了沿特定类型畴壁的平坦的、与偏置无关的态密度，这与该材料中传播的马约拉纳态的理论预测一致。尽管很难完全排除这一发现的拓扑微不足道的起源，但这项工作很可能会激发人们对铁基超导体作为马约拉纳州宿主的兴趣。科学，这个问题 p。104; 另见第。23 扫描隧道光谱表明沿 FeSe0.45Te0.55 表面的畴壁传播的 Majorana 状态。马约拉纳费米子在凝聚态物理学中作为准粒子激发的可能实现已经引起了极大的兴奋。大多数研究都集中在 Majorana 束缚态上；然而，也预测了具有线性色散的传播 Majorana 状态。在这里，我们报告了 FeSe0.45Te0.55 中晶体畴壁 (DW) 的扫描隧道光谱测量。我们找到了晶格结构移动半个晶胞的 DW。这些 DW 在超导间隙内具有有限、平坦的态密度，这是一维线性色散模式的标志。这种特征在相关超导体 FeSe 的 DW 中不存在，不在拓扑阶段。我们的组合数据与在邻近拓扑材料中以 π 相移 DW 分散马约拉纳态的观察结果一致。