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This content will become publicly available on April 23, 2019

Title: Dirac state in a centrosymmetric superconductor α - PdBi 2

Topological superconductor (TSC) hosting Majorana fermions has been established as a milestone that may shift our scientific trajectory from research to applications in topological quantum computing. Recently, superconducting Pd-Bi binaries have attracted great attention as a possible medium for the TSC phase as a result of their large spin-orbit coupling strength. Here, we report a systematic high-resolution angle-resolved photoemission spectroscopy (ARPES) study on the normal state electronic structure of superconducting α - PdBi 2 (T c = 1.7 K). Our results show the presence of Dirac states at higher-binding energy with the location of the Dirac point at 1.26 eV below the chemical potential at the zone center. Furthermore, the ARPES data indicate multiple band crossings at the chemical potential, consistent with the metallic behavior of α - PdBi 2. Our detailed experimental studies are complemented by first-principles calculations, which reveal the presence of surface Rashba states residing in the vicinity of the chemical potential. The obtained results provide an opportunity to investigate the relationship between superconductivity, topology, and the Majorana fermion, as well as explore pathways to possible future platforms for topological quantum computing.
Authors:
 [1] ;  [1] ;  [1] ; ORCiD logo [2] ;  [1] ;  [1] ;  [3] ;  [4] ; ORCiD logo [2] ;  [1]
  1. Univ. of Central Florida, Orlando, FL (United States). Dept. of Physics
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Polish Academy of Sciences, Wroclaw (Poland). Inst. of Low Temperature and Structure Research
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skłodowska Univ., Lublin (Poland). Inst. of Physics, Maria Curie
Publication Date:
Report Number(s):
LA-UR-17-26987
Journal ID: ISSN 2469-9950; PRBMDO
Grant/Contract Number:
AC52-06NA25396; 2015/18/A/ST3/00057
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 97; Journal Issue: 14; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF); National Science Centre (Poland)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; Material Science; spin-orbit coupling; superconductivity; topological quantum computing
OSTI Identifier:
1471354
Alternate Identifier(s):
OSTI ID: 1434345