Thermodynamically stable noncomposite vortices in mesoscopic two-gap superconductors

Abstract

In mesoscopic two-gap superconductors with sizes of the order of the coherence length noncomposite vortices are found to be thermodynamically stable in a large domain of the $T-H$ phase diagram. In these phases the vortex cores of one condensate are spatially separated from the other condensate ones, and their respective distributions can adopt distinct symmetries. The appearance of these vortex phases is caused by a non-negligible effect of the boundary of the sample on the superconducting order parameter and represents therefore a genuine mesoscopic effect. For low values of interband Josephson coupling vortex patterns with $L_1\ne L_2$ can arise in addition to the phases with $L_1=L_2$, where $L_1$ and $L_2$ are total vorticities in the two condensates. The calculations show that noncomposite vortices could be observed in thin mesoscopic samples of MgB${}_2$.

5 pages, 3 figures, to be published in Europhysics Letters

References in corpus (12)

• Vortices with fractional flux in two-gap superconductors and in extended Faddeev model
• Vortex phase diagram for mesoscopic superconducting disks
• Vortex Imaging in the pi-Band of Magnesium Diboride
• Experimental Evidence for Giant Vortex States in a Mesoscopic Superconducting Disk
• Ginzburg-Landau theory of vortices in a multi-gap superconductor
• Multiband model for penetration depth in MgB2
• Stable vortex-antivortex molecules in mesoscopic superconducting triangles
• Effects of neutron irradiation on polycrystalline Mg11B2
• Phase transitions in the mesoscopic superconducting square
• Dissociation of vortex stacks into fractional-flux vortices
• Anisotropy of the upper critical field in MgB2: the two-gap Ginzburg-Landau theory
• Weak inter-band coupling in Mg${}^{10}$B${}_2$: a specific heat analysis

Cited by in corpus (19)

• Type-1.5 Superconductors
• Vortex matter in mesoscopic two-gap superconducting disks: influence of Josephson and magnetic coupling
• Stable fractional flux vortices in mesoscopic superconductors
• Magnetic field delocalization and flux inversion in fractional vortices in two-component superconductors
• Skyrmionic state and stable half-quantum vortices in chiral p-wave superconductors
• Stable fractional flux vortices and unconventional magnetic state in two-component superconductors
• Stability of fractional vortex states in a two-band mesoscopic superconductor
• Ground state, collective mode, phase soliton and vortex in multiband superconductors
• Giant vortices, vortex rings and reentrant behavior in type-1.5 superconductors
• Vortex states in mesoscopic three-band superconductors
• Distinct magnetic signatures of fractional vortex configurations in multiband superconductors
• Comment on Phys. Rev. B 83, 054515 (2011) by V. G. Kogan and J. Schmalian and comment on their reply Phys. Rev. B 86, 016502 (2012)
• Microscopically derived multi-component Ginzburg-Landau theories for $s+is$ superconducting state
• Topological phase transitions in small mesoscopic chiral p-wave superconductors
• Coreless vortices as direct signature of chiral $d$-wave superconductivity
• Vortex motion and flux-flow resistivity in dirty multiband superconductors
• Robust and tunable coreless vortices and fractional vortices in chiral $d$-wave superconductors
• Topological defects in mixtures of superconducting condensates with different charges
• DC-driven separation of fractional flux quanta in two-band superconductors