標題: | Helical Majorana fermions in d(x2-y2) + id(xy)-wave topological superconductivity of doped correlated quantum spin Hall insulators |
作者: | Sun, Shih-Jye Chung, Chung-Hou Chang, Yung-Yeh Tsai, Wei-Feng Zhang, Fu-Chun 電子物理學系 Department of Electrophysics |
公開日期: | 11-四月-2016 |
摘要: | There has been growing interest in searching for exotic self-conjugate, charge-neutral low-energy fermionic quasi-particles, known as Majorana fermions (MFs) in solid state systems. Their signatures have been proposed and potentially observed at edges of topological superconcuctors with non-trivial topological invariant in the bulk electronic band structure. Much effort have been focused on realizing MFs in odd-parity superconductors made of strong spin-orbit coupled materials in proximity to conventional superconductors. In this paper, we propose a novel mechanism for realizing MFs in 2D spin-singlet topological superconducting state induced by doping a correlated quantum spin Hall (Kane-Mele) insulator. Via a renormalized mean-field approach, the system is found to exhibits time-reversal symmetry (TRS) breaking d(x2-y2) + id(xy)-wave (chiral d-wave) superconductivity near half-filling in the limit of large on-site repulsion. Surprisingly, however, at large spin-orbit coupling, the system undergoes a topological phase transition and enter into a new topological phase protected by a pseudo-spin Chern number, which can be viewed as a persistent extension of the quantum spin Hall phase upon doping. From bulk-edge correspondence, this phase is featured by the presence of two pairs of counter-propagating helical Majorana modes per edge, instead of two chiral propagating edge modes in the d + id' superconductors. |
URI: | http://dx.doi.org/10.1038/srep24102 http://hdl.handle.net/11536/133660 |
ISSN: | 2045-2322 |
DOI: | 10.1038/srep24102 |
期刊: | SCIENTIFIC REPORTS |
Volume: | 6 |
起始頁: | 0 |
結束頁: | 0 |
顯示於類別: | 期刊論文 |