Chiral d-wave superconducting state in the core of a doubly quantized s-wave vortex in graphene

Abstract

We show that the intrinsic chiral $d_{x^2-y^2}\pm i{d}_{xy}$-wave superconducting pairing in doped graphene is significantly strengthened in the core region of a doubly quantized s-wave superconducting vortex produced in a graphene-superconductor hybrid structure. The chiral d-wave state is induced by proximity effect, which transfers the center-of-mass angular momentum of the s-wave vortex to the orbital angular momentum of the chiral d-wave Cooper pairs. The proximity effect is enhanced by the circular geometry of the vortex and we find a $[1+(T-T_{c,J}{)}^2{]}^{-1}$ temperature dependence for the chiral d-wave core amplitude, where $T_{c,J}$ is its intrinsic bulk transition temperature. We further propose to detect the chiral d-wave state by studying the temperature dependence of the low-energy local density of states in the vortex core, which displays a sudden radial change as function of the strength of the d-wave core state.

6 pages, 3 figures. v2 minor changes

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Cited by in corpus (7)

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• Chiral d-wave superconductivity on the honeycomb lattice close to the Mott state
• i-Josephson Junction as Topological Superconductor
• Defects in the (d+id)-wave superconducting state in heavily doped graphene
• Probing vortex Majorana fermions and topology in semiconductor-superconductor heterostructures
• Robust and tunable coreless vortices and fractional vortices in chiral $d$-wave superconductors
• Enhanced chiral edge currents and orbital magnetic moment in chiral $d$-wave superconductors from mesoscopic finite-size effects