| Author(s): |
Niv Levy; Tong Zhang; Jeonghoon Ha; Fred Sharifi; Alec Talin; Young Kuk; Joseph A. Stroscio; |
| Title: |
Experimental Evidence for s-Wave Pairing Symmetry in Superconducting Cu_{x}Bi_{2}Se_{3} Single Crystals Using a Scanning Tunneling Microscope |
| Published: |
March 12, 2013 |
| Abstract: |
Topological superconductors (TS) are a newly predicted phase of matter which is topologically distinct from conventional superconducting condensates of Cooper pairs. As a manifestation of its topological character, TS supports massless itinerant quasi-particles on the boundary, which are solid-state realizations of Majorana fermions. The recently discovered superconductor CuxBi2Se3 has been theoretically proposed as an odd-parity superconductor in the time-reversal-invariant TS class. Here we report scanning tunneling spectroscopy (STS) measurements of the superconducting energy gap in CuxBi2Se3 as a function of spatial position and applied magnetic field. The tunneling spectrum shows that the density of states at the Fermi level is fully gapped without any in-gap states. The spectrum is well described by the Bardeen-Cooper-Schrieffer (BCS) theory with a momentum independent order parameter, which strongly suggests that Cu0.2Bi2Se3 is a classical s-wave superconductor contrary to previous expectations. |
| Citation: |
Physical Review Letters |
| Volume: |
110 |
| Issue: |
11 |
| Keywords: |
Topological superconductors;scanning tunneling microscopy;scanning tunneling spectroscopy |
| Research Areas: |
Characterization, Nanometrology, and Nanoscale Measurements |
| PDF version: |
 Click here to retrieve PDF version of paper (2MB) |
