Observation of topological surface states in the high-temperature superconductor MgB2

DOI: 10.1103/PhysRevB.100.184511

Authors: Xiaoqing Zhou (University of Colorado at Boulder) , Kyle N. Gordon (University of Colorado Boulder) , Kyung-hwan Jin (University of Utah) , Haoxiang Li (University of Colorado at Boulder) , Dushyant Narayan (University of Colorado at Boulder) , Hengdi Zhao (University of Colorado at Boulder) , Hao Zheng (University of Colorado at Boulder) , Huaqing Huang (University of Utah) , Gang Cao (University of Colorado at Boulder) , Nikolai D. Zhigadlo (University of Bern; CrystMat Company) , Feng Liu (University of Utah; Collaborative Innovation Center of Quantum Matter, Beijing) , Daniel Dessau (University of Colorado at Boulder)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 100

State: Published (Approved)
Published: November 2019
Diamond Proposal Number(s): 17595

Abstract: Most topological superconductors known to date suffer from low transition temperatures ( T c ) 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 T c = 39 K BCS superconductor MgB 2 . 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.

Journal Keywords: Topological superconductors; Angle-resolved photoemission spectroscopy; Density functional calculations; Condensed Matter & Materials Physics

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Other Facilities: Stanford Synchrotron Radiation Lightsource