Ground state, collective mode, phase soliton and vortex in multiband superconductors

Abstract

This article reviews theoretical and experimental work on the novel physics in multiband superconductors. Multiband superconductors are characterized by multiple superconducting energy gaps in different bands with interaction between Cooper pairs in these bands. The discovery of prominent multiband superconductors $\mathrm{Mg}{\mathrm{B}}_2$ and later iron-based superconductors has triggered enormous interests in multiband superconductors. Most recently discovered superconductors exhibit multiband features. The multiband superconductors possess novel properties that are not shared by their single-band counterpart. Examples include the time-reversal symmetry broken state in multiband superconductors with frustrated interband couplings, the collective oscillation of number of Cooper pairs between different bands, known as the Leggett mode, the phase soliton and fractional vortex, which are the main focus of this review. This review presents a survey of a wide range of theoretical exploration and experimental investigations of novel physics in multiband superconductors. Vast information derived from these studies is shown to highlight unusual and unique properties of multiband superconductors, and to reveal the challenges and opportunities in the research on the multiband superconductivity.

review article with 34 pages and 24 figures. Comments and suggestions are welcome

References in corpus (49)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• High-temperature superconductivity in iron-based materials
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report
• A minimal two-band model for the superconducting Fe-pnictides
• Direct coupling between magnetism and superconducting current in Josephson Phi junction
• Type-1.5 Superconductors
• Ginzburg-Landau theory of vortices in a multi-gap superconductor
• Exotic Superconducting Properties in the Electron-Hole Compensated Heavy Fermion `Semimetal' URu2Si2
• Limits of the upper critical field in dirty two-gap superconductors
• Pairing State with a time-reversal symmetry breaking in FeAs based superconductors
• Observation of Leggett's collective mode in a multi-band MgB2 superconductor
• Superfluid density and specific heat within self-consistent scheme for two-band superconductor
• Quasiparticle Heat Transport in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$: Evidence for a k-dependent Superconducting Gap without Nodes
• Chiral CP^2 skyrmions in three-band superconductors
• Magnetic response of mesoscopic superconducting rings with two order parameters
• Universality of superconducting gaps in overdoped Ba0.3K0.7Fe2As2 observed by angle-resolved photoemission spectroscopy
• Two-band superconductors: Hidden criticality deep in the superconducting state
• Theory of heterotic SIS Josephson junctions between single- and multi-gap superconductors
• Observability of a projected new state of matter: a metallic superfluid
• Phase textures induced by dc current pairbreaking in multilayer structures and two-gap superconductors
• Violation of the London Law and Onsager-Feynman quantization in multicomponent superconductors
• Conditions for non-monotonic vortex interaction in two-band superconductors
• Effect of annealing on the specific heat of Ba(Fe1-xCox)2As2
• Vortex sub-lattice melting in a two-component superconductor
• Stability of fractional vortex states in a two-band mesoscopic superconductor
• Nodeless superconductivity in K${}_x$Fe${}_{2-y}$Se${}_2$ single crystals revealed by low temperature specific heat
• Thermodynamically stable noncomposite vortices in mesoscopic two-gap superconductors
• Josephson effect between a two-band superconductor with the s++ or s+- pairing symmetry and a conventional s-wave superconductor
• Muon-spin rotation measurements of the vortex state in Sr${}_2$RuO${}_4$: type-1.5 superconductivity, vortex clustering and a crossover from a triangular to a square vortex lattice
• $\pi$-junction to probe antiphase s-wave pairing in iron pnictide superconductors
• Giant vortices, vortex rings and reentrant behavior in type-1.5 superconductors
• Collective modes in multiband superfluids and superconductors: Multiple dynamical classes
• Microwave Response of V3Si Single Crystals: Evidence for Two-Gap Superconductivity
• Dissociation Transition of a Composite Lattice of Magnetic Vortices in the Flux-Flow Regime of Two-Band Superconductors
• Theory of Raman scattering from Leggett's collective mode in a multiband superconductor: Application to MgB${}_2$
• Phase soliton and pairing symmetry of a two-band superconductor: Role of the proximity effect
• Stabilizing fractional vortices in multiband superconductors with periodic pinning arrays
• Anharmonicity and self-energy effects of the E2g phonon in MgB2
• Josephson Effects in Three-Band Superconductors with Broken Time-Reversal Symmetry
• Leggett mode in a strong-coupling model of iron arsenide superconductors
• Observation of a metallic superfluid in a numerical experiment
• Anomalous proximity effects at the interface of s and s+- superconductors
• Shapiro Steps as a Direct Probe of $\pm s$-wave Symmetry in Multi-gap Superconducting Josephson Junctions
• Phase diagram of Josephson junction between s and s+- superconductors in dirty limit
• Fluctuations in two-band superconductors in a strong magnetic field
• Type-1.5 superconductivity in muliband and other multicomponent systems
• Possible pi-phase shift at interface of two pnictides with antiphase s-wave pairing
• Three and Four-Body Intervortex Forces in the Ginzburg-Landau Models of Single- and Multicomponent Superconductivity

Cited by in corpus (6)

• Distinguishing between $s+id$ and $s+is$ pairing symmetries in multiband superconductors through spontaneous magnetization pattern induced by a defect
• Proximity and Josephson effects in microstructures based on multiband superconductors
• Topological phase transitions in small mesoscopic chiral p-wave superconductors
• Anomalous diamagnetic response in multi-band superconductors with time-reversal broken symmetry
• Skyrmionic chains and lattices in $s+id$ superconductors
• Frustration driven Josephson phase dynamics