@article{11989, author = {Xiaoqing Zhou and Kyle Gordon and Kyung-Hwan Jin and Haoxiang Li and Dushyant Narayan and Hengdi Zhao and Hao Zheng and Huaqing Huang and Gang Cao and Nikolai Zhigadlo and Feng Liu and Daniel Dessau}, title = {Observation of topological surface states in the high-temperature superconductor}, abstract = {Most topological superconductors known to date suffer from low transition temperatures (Tc) 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\ Tc=39\ K BCS superconductor\ MgB2. 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 = {2019}, journal = {Physical Review B}, volume = {100}, pages = {184511}, month = {2019-10}, issn = {2469-9950}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.100.184511}, doi = {10.1103/PhysRevB.100.184511}, }