Half-metallic Surface States and Topological Superconductivity in
Year: 2011
Type: preprint
Abstract: Majorana fermions obey non-Abelian statistics, which is the key ingredient for the fault-tolerant topological quantum computation [1–3]. Recently, they have been proposed to exist in various condensed-matter systems [4–8] as emergent excitations. However, experimental realization in these materials remains challenging. For a halfmetal, which acts as conductor for one spin and insulator for another spin [9], the proximity effect with a s-wave superconductor can induce topological px + ipy superconductivity and Majorana fermions in the vortex core [10]. In this work we predict a novel half-metallic surface state in layered bulk insulator NaCoO2, with tunable surface hole concentration. The half-metallic surface has a single fermi surface with a helical spin texture, similar to the surface state of topological insulators[11–13], but with the key difference of time reversal symmetry breaking in the present case. We propose realization of topological superconductivity and Majorana fermions when the half-metallic surface states are in proximity contact with a conventional superconductor.
Source: arXiv (Cornell University)
Authors: Hongming Weng, Gang Xu, Haijun Zhang, Shengbai Zhang, Xi Dai, Zhong Fang
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2611795463