Spin-triplet<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:math>-wave local pairing induced by Hund’s rule coupling

Han, Jong E.

doi:10.1103/physrevb.70.054513

Cited by 50 publications

(21 citation statements)

References 28 publications

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“…For a fixed total occupation of a given site, the interaction J differentiates between the energies of different orbital occupation and spin states. In a lattice environment, this can lead to considerable shifts in the metal-Mott insulator phase boundaries [2,3], to local moment formation [4], nonlocal correlation effects [5,6], and various types of symmetry breaking [7][8][9][10][11][12][13]. Already in the two-band case, nontrivial crossovers and phase transitions can be observed.…”

Section: Introductionmentioning

confidence: 99%

Long-range orders and spin/orbital freezing in the two-band Hubbard model

et al. 2016

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We solve the orbitally degenerate two-band Hubbard model within dynamical mean field theory and map out the instabilities to various symmetry-broken phases based on an analysis of the corresponding lattice susceptibilities. Phase diagrams as a function of the Hund coupling parameter J are obtained both for the model with rotationally invariant interaction and for the model with Ising-type anisotropy. For negative J , an intraorbital spin-singlet superconducting phase appears at low temperatures, while the normal state properties are characterized by an orbital-freezing phenomenon. This is the negative-J analog of the recently discovered fluctuating-moment induced s-wave spin-triplet superconductivity in the spin-freezing regime of multiorbital models with J > 0.

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Section: Introductionmentioning

confidence: 99%

Long-range orders and spin/orbital freezing in the two-band Hubbard model

et al. 2016

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“…In the case of correlated and orbitally degenerate lattice systems the intra-atomic ferromagnetic (Hundʼs rule) exchange interaction of magnitude J 0.1 ≳ eV, appears naturally and is essential to the description of ferromagnetism, for moderately and strongly correlated electrons. Furthermore, its significance to the spin-triplet pairing has been emphasized in general [13][14][15][16][17], as well as for both the pnictides [6] and Sr RuO 2 4 [18,19]. In most cases, the Hundʼs rule in conjunction with remaining local Coulomb interactions are either treated in the Hartree-Fock approximation [20] or a semi-phenomenological negative-U intersite attraction [21] is introduced.…”

Section: Introductionmentioning

confidence: 99%

Even-parity spin-triplet pairing by purely repulsive interactions for orbitally degenerate correlated fermions

2014

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We demonstrate the stability of the spin-triplet paired s-wave (with an admixture of extended s-wave) state for the limit of purely repulsive interactions in a degenerate two-band Hubbard model of correlated fermions. The repulsive interactions limit represents an essential extension of our previous analysis (2013 New J. Phys. 15 073050), regarded here as I. We also show that near the halffilling the considered type of superconductivity can coexist with antiferromagnetism. The calculations have been carried out with the use of the socalled statistically consistent Gutzwiller approximation (SGA) for the case of a square lattice. We suggest that the electron correlations in conjunction with the Hundʼs rule exchange play the crucial role in stabilizing the real-space spintriplet superconducting state. A sizable hybridization of the bands suppresses the homogeneous paired state.

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“…In this manner, the paper extends the discussion of itinerant magnetism within the canonical (extended Hubbard) model, appropriate for this purpose, to the analysis of pure and coexisting superconducting-magnetic states within a single unified approach. It should be noted that theoretical investigations regarding the spin-triplet pairing have been performed recently also for other systems [30][31][32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Coexistence of spin-triplet superconductivity with magnetism within a single mechanism for orbitally degenerate correlated electrons: statistically consistent Gutzwiller approximation

2013

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An orbitally degenerate two-band Hubbard model is analyzed with the inclusion of the Hund's rule-induced spin-triplet even-parity paired states and their coexistence with magnetic ordering. The so-called statistically consistent Gutzwiller approximation (SGA) has been applied to the case of a square lattice. The superconducting gaps, the magnetic moment and the free energy are analyzed as a function of the Hund's rule coupling strength and the band filling. Also, the influence of the intersite hybridization on the stability of paired phases is discussed. In order to examine the effect of correlations the results are compared with those calculated earlier within the Hartree-Fock (HF) approximation combined with the Bardeen-Cooper-Schrieffer (BCS) approach. Significant differences between the two methods used (HF + BCS versus SGA+real-space pairing) appear in the stability regions of the considered phases. Our results supplement the analysis of this canonical model used

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Spin-triplets-wave local pairing induced by Hund’s rule coupling

Cited by 50 publications

References 28 publications

Long-range orders and spin/orbital freezing in the two-band Hubbard model

Long-range orders and spin/orbital freezing in the two-band Hubbard model

Even-parity spin-triplet pairing by purely repulsive interactions for orbitally degenerate correlated fermions

Coexistence of spin-triplet superconductivity with magnetism within a single mechanism for orbitally degenerate correlated electrons: statistically consistent Gutzwiller approximation

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