2014/10/31 by Yuki Nagai · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Quantum many-body systems #Topological Materials and Phenomena #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.91.060502
published as Phys. Rev. B 91, 060502(R) (2015) · 4 pages, 4 figures. Accepted for publication in PRB Rapid Communications
arxiv created 2015/01/26 · openalex publication_date 2015/02/05 · arxiv updated 2015/02/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study the robustness against nonmagnetic impurities in the topological superconductor with point nodes, focusing on an effective model of CuxBi2Se3. We find that the topological superconductivity with point nodes is not fragile against nonmagnetic impurities, although the superconductivity with nodes in past studies is usually fragile. Exchanging the role of spin with the one of orbital, and vice versa, we find that in the ``dual'' space the topological superconductor with point nodes is regarded as the intraorbital spin-singlet s-wave one. From the viewpoint of the dual space, we deduce that the point-node state is not fragile against nonmagnetic impurity, when the orbital imbalance in the normal states is small. Since the spin imbalance is induced by the Zeeman magnetic field, we shall name this key quantity for the impurity effects the Zeeman ``orbital'' field. The numerical calculations support that the deduction is correct. If the Zeeman orbital field is small, the topological superconductivity is not fragile in dirty materials, even with nodes. Thus, the topological superconductors cannot be simply regarded as one of the conventional unconventional superconductors.