Observation of topological surface states in the high-temperature superconductor

Author
Abstract
Most topological superconductors known to date suffer from low transition temperatures (T<sub>c</sub>) and/or high fragility to disorder and dopant levels, which is hampering the progress in this promising field. Here, utilizing a combination of angle-resolved photoemission spectroscopy measurements and density-functional theory calculations, we show the presence of a type of topological Dirac nodal line surface state on the [010] faces of the\&nbsp;T<sub>c</sub>=39\&nbsp;K BCS superconductor\&nbsp;MgB<sub>2</sub>. This surface state should be highly tolerant against disorder and inadvertent doping variations and is expected to go superconducting via the proximity effect to the bulk superconductor that this state is intimately connected to. This would represent a form of high-temperature topological superconductivity.
Year of Publication
2019
Journal
Physical Review B
Volume
100
Date Published
2019-10
ISSN Number
2469-9950
URL
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.100.184511
DOI
10.1103/PhysRevB.100.184511
JILA PI
Journal Article