Abstract
Majorana zero modes (MZMs) are spatially localized, zero-energy fractional quasiparticles with non-Abelian braiding statistics that hold promise for topological quantum computing. Owing to the particle-antiparticle equivalence, MZMs exhibit quantized conductance at low temperature. By using variable-tunnel-coupled scanning tunneling spectroscopy, we studied tunneling conductance of vortex bound states on FeTe0.55Se0.45 superconductors. We report observations of conductance plateaus as a function of tunnel coupling for zero-energy vortex bound states with values close to or even reaching the 2e2/h quantum conductance (where e is the electron charge and h is Planck's constant). By contrast, no plateaus were observed on either finite energy vortex bound states or in the continuum of electronic states outside the superconducting gap. This behavior of the zero-mode conductance supports the existence of MZMs in FeTe0.55Se0.45
| Original language | English |
|---|---|
| Pages (from-to) | 189-192 |
| Number of pages | 4 |
| Journal | Science |
| Volume | 367 |
| Issue number | 6474 |
| DOIs | |
| State | Published - Jan 10 2020 |
| Externally published | Yes |
Funding
We thank P. A. Lee, C.-X. Liu, and G. Su for helpful discussions and A.-W. Wang, J.-H. Yan, and Q. Huan for technical assistance. Funding: The work at IOP is supported by grants from the Ministry of Science and Technology of China (2019YFA0308500, 2015CB921000, 2015CB921300, and 2016YFA0202300), the National Natural Science Foundation of China (61888102 and 11888101), and the Chinese Academy of Sciences (XDB28000000, XDB30000000, and 112111KYSB20160061). L.F. and G.G. are supported by the U.S. Department of Energy (DOE) (DE-SC0019275 and DE-SC0012704, respectively). J.S. and R.Z. are supported by the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by the DOE.