Identifying detrimental effects for multiorbital superconductivity: Application to<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Sr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>RuO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>

Ramires, Aline; Sigrist, Manfred

doi:10.1103/physrevb.94.104501

Cited by 113 publications

(109 citation statements)

References 20 publications

Supporting

Mentioning

103

Contrasting

Order By: Relevance

“…24, singlet pairing is proposed to account for the behavior of the upper critical field, which however could also be reconciled in the picture of triplet pairing. 41 Moreover, singlet pairing is inconsistent with the earlier strong evidences for triplet pairing. [11][12][13][14] A closer comparison between theory and experiment can be made by referencing our results to the strain level ε L for the Lifshitz reconstruction.…”

Section: Discussioncontrasting

confidence: 52%

Theory of the evolution of superconductivity in Sr2RuO4 under anisotropic strain

et al. 2017

View full text Add to dashboard Cite

Sr 2 RuO 4 is a leading candidate for chiral p-wave superconductivity. The detailed mechanism of superconductivity in this material is still the subject of intense investigations. Since superconductivity is sensitive to the topology of the Fermi surface (the contour of zero-energy quasi-particle excitations in the momentum space in the normal state), changing this topology can provide a strong test of theory. Recent experiments tuned the Fermi surface topology efficiently by applying planar anisotropic strain. Using functional renormalization group theory, we study the superconductivity and competing orders in Sr 2 RuO 4 under strain. We find a rapid initial increase in the superconducting transition temperature T c , which can be associated with the evolution of the Fermi surface toward a Lifshitz reconstruction under increasing strain. Before the Lifshitz reconstruction is reached, however, the system switches from the superconducting state to a spin density wave state. The theory agrees well with recent strain experiments showing an enhancement of T c followed by an intriguing sudden drop.

show abstract

Section: Discussioncontrasting

confidence: 52%

Theory of the evolution of superconductivity in Sr2RuO4 under anisotropic strain

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Finally, although there is strong evidence for the timereversal symmetry breaking (TRSB) chiral p-wave superconductivity in Sr 2 RuO 4 , [26][27][28][29][30] difficulties remain in reconciling the expectations for this order and a few key experiments, including the puzzling absence [31][32][33][34] (or smallness 35 ) of spontaneous edge current (although recent years have seen numerous attempts to explain the absence of edge current [36][37][38][39][40][41][42] ), the anomalous suppression of the in-plane upper critical field H c2 43 and indications of a first order transition for in-plane H c2 at low temperatures 44 (see Ramires et al 45 for a recent attempt to explain this). It is thus tempting to ask whether Sr 2 RuO 4 could in fact support an alternative TRSB oddparity superconducting order, made possible by the multiband nature, 46 analogous to what has been discussed in the context of MgCNi 3 , 47 some iron-based superconductors, [48][49][50] and SrPtAs.…”

mentioning

confidence: 99%

Leggett modes and multiband superconductivity inSr2RuO4

Huang

Scaffidi²,

Sigrist

et al. 2016

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

Sr2RuO4 is a prototypical multi-band superconductor with three bands crossing the Fermi level. These bands exhibit distinct dimensional characteristics, with one quasi-2D γ-band and two quasi-1D α-and β-bands. This leads to the expectation that the superconductivity on the γ-band may be only weakly Josephson-coupled to that on the other two bands. Based on an explicit microscopic weak coupling calculation appropriate for Sr2RuO4, we study the collective Leggett modes associated with the relative phase oscillations between the bands and show that a relatively soft Leggett mode exists due to the comparatively weaker inter-band Josephson coupling. These calculations also provide insight into why the superconducting gap magnitudes may be comparable on all three bands, despite the noticeable differences between the γ and α/β bands. The analyses can be readily applied to other multi-band superconductors.Multi-band superconductors possess physical properties that are not present in single-band superconductors. Depending on the nature of the interactions driving the Cooper pairing and the orbital character of the bands, the superconducting order parameter may not be dominated by one band with only much weaker induced superconductivity on the other bands. This is particularly so in multi-band systems with unconventional pairing symmetry, where the correlations underlying the superconductivity often involve electrons on different bands strongly interacting with each other. These inter-band interactions give rise to effective Josephson couplings between the superconducting order parameters of the different bands 1 . As a consequence, in the ground state, the multiple order parameters are locked in a configuration with a particular set of relative phases and magnitudes.Under external perturbations or at finite temperatures, the relative phase between the multiple order parameters can fluctuate, costing a finite amount of energy that is determined by the inter-band couplings. These collective excitations are commonly referred to as Leggett modes.1 They respond to electromagnetic fields in a peculiar manner, and are unlike the usual global U(1) phase fluctuations which are pushed up to the plasma frequency due to Coulomb interactions. 2 The putative chiral p-wave superconductor Sr 2 RuO 4 3-5 is a prototypical multi-band system, with three bands crossing the Fermi energy -two quasi one dimensional (1D) α/β-bands and one quasi two dimensional (2D) γ-band (Fig. 1). 9The quasi-1D bands originate primarily from the hybridized 4d xz and yz-orbitals, while the γ-band is dominated by the xy-orbital. These orbitals are further mixed by spin-orbit coupling. [6][7][8] The exact superconducting gap structure in this material is an ongoing debate. [9][10][11] In spite of this, a few things can be said regarding the effective interactions between the low energy fermions on the three Fermi surfaces. Firstly, the intraband Cooper pair scattering on the quasi-1D bands may be markedly different from that on the quasi-2D band. This could lead ...

show abstract

“…Details on the derivation of this relation can be found in reference [13]. Applying this concept to Sr 2 RuO 4 we find that the most compatible triplet superconducting (SC) state has the d-vector oriented along the z-axis, as a consequence of the interplay of interorbital hopping and spin-orbit coupling [13].…”

Section: Introductionmentioning

confidence: 99%

“…For example, singlet superconductivity is suppressed by the application of an external magnetic field, while triplet superconductivity is not robust in presence of certain inversion symmetry breaking fields. Recently [13,14], the authors showed that these criteria cannot be directly transferred to multi-orbital system, and introduce the concept of superconducting fitness to address the question of stability of superconductivity in arbitrarily complex multi-orbital systems. With this tool in hand we can evaluate the stability of different gap structures in presence of inter-orbital effects and external symmetry breaking fields, leading to robust arguments to be contrasted with experiments.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A note on the upper critical field of Sr₂RuO₄ under strain

Ramires

Sigrist

2017

J. Phys.: Conf. Ser.

Self Cite

View full text Add to dashboard Cite

In the light of the recently discussed mechanism for suppression of superconductivity in multi-orbital systems called inter-orbital effect, here we extend our analysis of the upper critical field in Sr2RuO4 now under strain. We show that the presence of the standard orbital effect and the new mechanism can consistently account for the qualitative changes observed in the upper critical field for the strained system, in particular, combining the overall enhancement of the critical field with the reduction in the anisotropy. The proposed picture holds for a triplet superconducting state, showing that a singlet state is not the only possibility to account for the observations. We suggest further experiments in order to clarify our understanding about the superconducting phase of Sr2RuO4.

show abstract

Identifying detrimental effects for multiorbital superconductivity: Application toSr2RuO4

Cited by 113 publications

References 20 publications

Theory of the evolution of superconductivity in Sr2RuO4 under anisotropic strain

Theory of the evolution of superconductivity in Sr2RuO4 under anisotropic strain

Leggett modes and multiband superconductivity inSr2RuO4

A note on the upper critical field of Sr₂RuO₄ under strain

Contact Info

Product

Resources

About

Identifying detrimental effects for multiorbital superconductivity: Application toSr2RuO4

Cited by 113 publications

References 20 publications

Theory of the evolution of superconductivity in Sr2RuO4 under anisotropic strain

Theory of the evolution of superconductivity in Sr2RuO4 under anisotropic strain

Leggett modes and multiband superconductivity inSr2RuO4

A note on the upper critical field of Sr2RuO4 under strain

Contact Info

Product

Resources

About

A note on the upper critical field of Sr₂RuO₄ under strain