Engineering of mixed pairing and non-Abelian Majorana states in chiral p-wave superconductor Sr2RuO4 and other materials

[摘要] This project deals with odd-parity superconductor Sr₂RuO₄ and related material systems, aiming at understanding the unconventional nature of superconductivity in this material. An odd-parity superconductor is expected to feature a novel topological object, the half-flux-quantum vortex that hosts a Majorana anyons. Majorana anyons carry non-Abelian statistics that can be used are the building block for constructing a fault-tolerated topological quantum computer. Half-flux-quantum vortices form in an odd-parity superconductor because of the availability of charge neutral spin supercurrent in addition to the normal supercurrent. Half-height magnetization steps were found in a cantilever magnetometry measurement of doubly connected mesoscopic samples of Sr₂RuO₄ in the presence of an in-plane magnetic field (J. Jang, D. G. Ferguson, V. Vakaryuk, R. Budakian, S. B. Chung, P. M. Goldbart, and Y. Maeno, Science 331, 186 (2011)), which suggests the presence of a half-flux-quantum (??₀/2 = h/4e) state. Evidence for half flux quantum states, which can be viewed as coreless half vortices, was obtained in mesoscopic samples of Sr₂RuO₄ in the torque magnetomitry measurements. However, the existence of such an important property has not been confirmed by any other independent measurement.

[发布日期] 2015-11-30

[学科分类] 凝聚态物理