PT  - JOURNAL ARTICLE
AU  - Wang, Zhenyu
AU  - Rodriguez, Jorge Olivares
AU  - Jiao, Lin
AU  - Howard, Sean
AU  - Graham, Martin
AU  - Gu, G. D.
AU  - Hughes, Taylor L.
AU  - Morr, Dirk K.
AU  - Madhavan, Vidya
TI  - Evidence for dispersing 1D Majorana channels in an iron-based superconductor
AID  - 10.1126/science.aaw8419
DP  - 2020 Jan 03
TA  - Science
PG  - 104--108
VI  - 367
IP  - 6473
4099  - http://science.sciencemag.org/content/367/6473/104.short
4100  - http://science.sciencemag.org/content/367/6473/104.full
SO  - Science2020 Jan 03; 367
AB  - 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. 23The 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.