Unconventional multi-band superconductivity in bulk SrTiO${}_3$ and LaAlO${}_3$/SrTiO${}_3$ interfaces

Abstract

Although discovered many decades ago, superconductivity in doped SrTiO${}_3$ remains a topic of intense research. Recent experiments revealed that, upon increasing the carrier concentration, multiple bands cross the Fermi level, signaling the onset of Lifshitz transitions. Interestingly, $T_c$ was observed to be suppressed across the Lifshitz transition of oxygen-deficient SrTiO${}_3$; a similar behavior was also observed in gated LaAlO${}_3$/SrTiO${}_3$ interfaces. Such a behavior is difficult to explain in the clean theory of two-band superconductivity, as the additional electronic states provided by the second band should enhance $T_c$. Here, we show that this unexpected behavior can be explained by the strong pair-breaking effect promoted by disorder, which takes place if the inter-band pairing interaction is subleading and repulsive. A consequence of this scenario is that, upon moving away from the Lifshitz transition, the two-band superconducting state changes from opposite-sign gaps to same-sign gaps.

arXiv comment5 pages, 4 figures

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Cited by in corpus (29)

• Superconductivity in dilute SrTiO${}_3$: a review
• Crystalline Nodal Topological Superconductivity and Bogolyubov Fermi Surfaces in Monolayer NbSe${}_2$
• Anisotropic superconductivity mediated by ferroelectric fluctuations in cubic systems with spin-orbit coupling
• Multiorbital Ferroelectric Superconductivity in doped SrTiO3
• Phonon mediated superconductivity in low carrier-density systems
• Cross-band versus intra-band pairing in superconductors: signatures and consequences of the interplay
• Weak-Coupling Theory of Pair Density-Wave Instabilities in Transition Metal Dichalcogenides
• Low Temperature Specific Heat of Doped SrTiO${}_3$: Doping Dependence of the Effective Mass and Kadowaki-Woods Scaling Violation
• Interplay between superconductivity and itinerant magnetism in underdoped Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ ($x=$ 0.2) probed by the response to controlled point-like disorder
• Gate-tunable hallmarks of unconventional superconductivity in non-centrosymmetric nanowires
• Implicit renormalization approach to the problem of Cooper instability
• Superconducting dome in the LaAlO${}_3$/SrTiO${}_3$ interfaces as a direct effect of the extended s-wave symmetry of the gap
• Anomalous Josephson Coupling and High-Harmonics in Non-Centrosymmetric Superconductors with $S$-wave Spin-Triplet Pairing
• Post-quench gap dynamics of two-band superconductors
• Constrained weak-coupling superconductivity in multiband superconductors
• Interplay between singlet and triplet pairings in multi-band two-dimensional oxide superconductors
• Bimodal Phase Diagram of the Superfluid Density in LaAlO3/SrTiO3 Revealed by an Interfacial Waveguide Resonator
• Kohn-Luttinger Correction to Tc in a Phonon Superconductor
• Impact of disorder on the superconducting transition temperature near a Lifshitz transition
• Potential Lifshitz transition at optimal substitution in nematic pnictide Ba${}_{1-x}$Sr${}_x$Ni${}_2$As${}_2$
• Interplay between the extended s-wave symmetry of the gap and the spin-orbit coupling in the low-electron concentration regime of quasi-two-dimensional superconductors
• Ferroelectricity-induced multiorbital odd-frequency superconductivity in SrTiO${}_3$
• Superconducting dome in doped 2D superconductors with broken inversion symmetry
• Effects of paramagnetic pair-breaking and spin-orbital coupling on multi-band superconductivity
• Intersubband pairing induced Fulde-Ferrell phase in metallic nanofilms
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• Unconventional superconducting correlations in fermionic many-body scars
• Modulation of superconductivity by quantum confinement in doped strontium titanate
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