Vortices with Fractional Flux Quanta in Multi-Band Superconductors

Huang, Zhao Hui; Hu, Xiao

doi:10.1007/s10948-015-3309-x

Cited by 4 publications

(3 citation statements)

References 33 publications

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“…Because of their unusual properties such superconductors (SC) with broken time-reversal symmetry (BTRS) are attracting a lot of attention. For instance recently the formation of new collective modes 1,2 (similarly to the occurrence of Leggett modes in two-band SC) and new topological excitations in the form of phase kinks, domains and vortices that carry fractional magnetic flux values [3][4][5][6][7][8][9][10][11][12] have been discussed.…”

Section: Introductionmentioning

confidence: 99%

Anomalous diamagnetic response in multiband superconductors with broken time-reversal symmetry

et al. 2017

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Within a Ginzburg-Landau formalism we establish analytically the necessary and sufficient conditions to realize a doubly degenerate superconducting ground state with broken time-reversal symmetry (BTRS) in a multi-band superconductor. Using these results we analyze the ground state of a three band superconductor in the cylindrical geometry in an external magnetic field. We show that depending on the interband coupling constants, a magnetic flux can induce current density jumps in such superconducting geometries that are related to adiabatic or non-adiabatic transitions from BTRS to time-reversal symmetric states and vice versa. This unusual current induced magnetic flux response can in principle be used experimentally to detect superconducting BTRS ground states as well as corresponding metastable excited states. arXiv:1707.02345v1 [cond-mat.supr-con]

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Section: Introductionmentioning

confidence: 99%

Anomalous diamagnetic response in multiband superconductors with broken time-reversal symmetry

et al. 2017

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“…In Refs. [58,59,59], Josephson junctions between chiral and regular superconductors were considered: the asymmetric critical currents, subharmonic Shapiro steps, symmetric Fraunhofer patterns [58], and the fractional flux and its plateau in magnetization curve [59,60] are studied by using Bogoliubov-de Gennes and the time-dependent Ginzburg-Landau equation. Also, in Ref.…”

Section: Summary and Discussionmentioning

confidence: 99%

Field theoretical model of multilayered Josephson junction and dynamics of Josephson vortices

Fujimori¹,

Iida²,

Nitta³

2016

Phys. Rev. B

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Multilayered Josephson junctions are modeled in the context of a field theory, and dynamics of Josephson vortices trapped inside insulators are studied. Starting from a theory consisting of complex and real scalar fields coupled to a U(1) gauge field which admit parallel N − 1 domain-wall solutions, Josephson couplings are introduced weakly between the complex scalar fields. The N − 1 domain walls behave as insulators separating N superconductors, where one of the complex scalar fields has a gap. We construct the effective Lagrangian on the domain walls, which reduces to a coupled sine-Gordon model for well-separated walls and contains more interactions for walls at short distance. We then construct sine-Gordon solitons emerging in an effective theory in which we identify Josephson vortices carrying singly quantized magnetic fluxes. When two neighboring superconductors tend to have the same phase, the ground state does not change with the positions of domain walls (the width of superconductors). On the other hand, when two neighboring superconductors tend to have π -phase differences, the ground state has a phase transition depending on the positions of domain walls; when the two walls are close to each other (one superconductor is thin), frustration occurs because of the coupling between the two superconductors besides the thin superconductor. Focusing on the case of three superconductors separated by two insulators, we find for the former case that the interaction between two Josephson vortices on different insulators changes its nature, i.e., attractive or repulsive, depending on the positions of the domain walls. In the latter case, there emerges fractional Josephson vortices when two degenerate ground states appear due to spontaneous charge-symmetry breaking, and the number of the Josephson vortices varies with the position of the domain walls. Our predictions should be verified in multilayered Josephson junctions.

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“…Iron-based superconductors have provided a key laboratory showing exotic superconducting phases characterized by inhomogeneity, nematic phases and multiple gaps [64][65][66][67][68][69]. The physics of the BCS-BEC crossover in quantum condensates in particular real space or k space spots widely studied in ultracold gases is now emerging as a generic feature in multiple condensates superconductors [70][71][72][73][74][75][76]. Understanding the emergence of novel spin-orbital phases [77] is now recognized to be a key ingredient for understanding high temperature superconductors and the advances in this field are now pushing the developments of spintronics and new quantum electronics [78][79][80][81][82][83].…”

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confidence: 99%

Complex Lattice and Charge Inhomogeneity Favoring Quantum Coherence in High-Temperature Superconductors

Bianconi

2016

J Supercond Nov Magn

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The presence of two components in the electron fluid of high temperature superconductors and the complex charge and lattice inhomogeneity have been the hot topics of the international conference of the superstripes series, Superstripes 2015, held in Ischia in 2015. The debate on the mechanisms for reaching room temperature superconductors has been boosted by the discovery of superconductivity with the highest critical temperature in pressurized sulfur hydride. Different complex electronic and structural landscapes showing up in superconductors, which resist to the decoherence effects of high temperature, have been discussed. While low temperature superconductors described by the BCS approximation are made of a single condensate in the weak coupling the high temperature superconductors are made of coexisting multiple condensates (in different spots of the k--space and the real space) some in the BCS--BEC crossover regime and others in the BCS regime. The role of "shape resonance" in the exchange interaction between these different condensates, like "the Fano--Feshbach resonance" in ultracold gasses, is emerging as a key term for high temperature superconductivity.

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Vortices with Fractional Flux Quanta in Multi-Band Superconductors

Cited by 4 publications

References 33 publications

Anomalous diamagnetic response in multiband superconductors with broken time-reversal symmetry

Anomalous diamagnetic response in multiband superconductors with broken time-reversal symmetry

Field theoretical model of multilayered Josephson junction and dynamics of Josephson vortices

Complex Lattice and Charge Inhomogeneity Favoring Quantum Coherence in High-Temperature Superconductors

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