A topological superconductor (TSC) is characterized by the topologically-protected gapless surface state that is essentially an Andreev bound state consisting of Majorana fermions. While a TSC has not yet been discovered, the doped topological insulator CuxBi2Se3, which superconducts below ~3 K, has been predicted to possess a topological superconducting state. We report that the point-contact spectra on the cleaved surface of superconducting CuxBi2Se3 present a zero-bias conductance peak (ZBCP) which signifies unconventional superconductivity. Theoretical considerations of all possible superconducting states help us conclude that this ZBCP is due to Majorana Fermions and gives evidence for a topological superconductivity in CuxBi2Se3. In addition, we found an unusual pseudogap that develops below ~20 K and coexists with the topological superconducting state.
@article{arxiv.1108.1101,
title = {Topological Superconductivity in CuxBi2Se3},
author = {Satoshi Sasaki and M. Kriener and Kouji Segawa and Keiji Yada and Yukio Tanaka and Masatoshi Sato and Yoichi Ando},
journal= {arXiv preprint arXiv:1108.1101},
year = {2011}
}
Comments
5 pages, 4 figures (paper proper) + 10 pages, 10 figures (supplemental material); final version accepted for publication in PRL