Multiple nodeless superconducting gaps in optimally-doped SrTi${}_{1-x}$Nb${}_x$O${}_3$

Abstract

We present the first study of thermal conductivity in superconducting SrTi${}_{1-x}$Nb${}_x$O${}_3$, sufficiently doped to be near its maximum critical temperature. The bulk critical temperature, determined by the jump in specific heat, occurs at a significantly lower temperature than the resistive T${}_c$. Thermal conductivity, dominated by the electron contribution, deviates from its normal-state magnitude at bulk T${}_c$, following a Bardeen-Rickayzen-Tewordt (BRT) behavior, expected for thermal transport by Bogoliubov excitations. Absence of a T-linear term at very low temperatures rules out the presence of nodal quasi-particles. On the other hand, the field dependence of thermal conductivity points to the existence of at least two distinct superconducting gaps. We conclude that optimally-doped strontium titanate is a multigap nodeless superconductor.

6 pages including a supplement

References in corpus (22)

• Quantum criticality in ferroelectrics
• Heat Conduction in the Vortex State of NbSe_2: Evidence for Multi-Band Superconductivity
• Heat Transport in a Strongly Overdoped Cuprate: Fermi Liquid and Pure d-wave BCS Superconductor
• Locally enhanced conductivity due to the tetragonal domain structure in LaAlO${}_3$/SrTiO${}_3$ heterointerfaces
• Universal Heat Conduction in YBa_2Cu_3O_6.9
• Common Fermi-liquid origin of T-squared resistivity and superconductivity in n-type SrTiO3
• Universal heat conduction in the iron-arsenide superconductor KFe2As2 : Evidence of a d-wave state
• Critical doping for the onset of a two-band superconducting ground state in SrTiO${}_{3-\delta }$
• Thermal conductivity of single crystalline MgB_2
• Local Electrostatic Imaging of Striped Domain Order in LaAlO3/SrTiO3
• Fermi surface of the most dilute superconductor
• Microscopic derivation of two-component Ginzburg-Landau model and conditions of its applicability in two-band systems
• Thermal Conductivity of superconducting (TMTSF)_2ClO_4: evidence for a nodeless gap
• Unpaired Electrons in the Heavy-Fermion Superconductor CeCoIn_{5}
• Heat Conduction in $\kappa$-(BEDT-TTF)${}_2$Cu(NCS)${}_2$
• Heat transport as a probe of superconducting gap structure
• Universal Heat Transport in Sr2RuO4
• Twofold spontaneous symmetry breaking in a heavy fermion superconductor UPt${}_3$
• Two-band superconductivity in doped SrTiO${}_3$ films and interfaces
• Effect of controlled disorder on quasiparticle thermal transport in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_8$
• Heat transport in Bi_{2+x}Sr_{2-x}CuO_{6+δ}: departure from the Wiedemann-Franz law in the vicinity of the metal-insulator transition
• Isotropic three-dimensional gap in the iron-arsenide superconductor LiFeAs from directional heat transport measurements

Cited by in corpus (24)

• A ferroelectric quantum phase transition inside the superconducting dome of Sr${}_{1-x}$Ca${}_x$TiO${}_{3-\delta }$
• Thermal transport and phonon hydrodynamics in strontium titanate
• Phonon thermal Hall effect in strontium titanate
• Metallicity and superconductivity in doped strontium titanate
• Single-gap superconductivity and dome of superfluid density in Nb-doped SrTiO3
• Unconventional multi-band superconductivity in bulk SrTiO${}_3$ and LaAlO${}_3$/SrTiO${}_3$ interfaces
• Superfluid density and carrier concentration across a superconducting dome: the case of SrTi${}_{1-x}$Nb${}_x$O${}_3$
• On the origin and the amplitude of T-square resistivity in Fermi liquids
• Multiorbital Ferroelectric Superconductivity in doped SrTiO3
• Enhanced Superconducting Transition Temperature due to Tetragonal Domains in Two-Dimensionally Doped SrTiO${}_3$
• Interplay between antiferrodistortive, ferroelectric and superconducting instabilities in Sr_{1-x}Ca_{x}$TiO_{3-δ}
• Isotope tuning of the superconducting dome of strontium titanate
• Heavy non-degenerate electrons in doped strontium titanate
• S-wave Superconductivity in Optimally Doped SrTi${}_{1-x}$Nb${}_x$O${}_3$ Unveiled by Electron Irradiation
• Low Temperature Specific Heat of Doped SrTiO${}_3$: Doping Dependence of the Effective Mass and Kadowaki-Woods Scaling Violation
• Superconductivity enhancement in polar metal regions of Sr${}_{0.95}$Ba${}_{0.05}$TiO${}_3$ and Sr${}_{0.985}$Ca${}_{0.015}$TiO${}_3$ revealed by the systematic Nb doping
• Supercondutivity in SnSb with natural superlattice structure
• Nernst response, viscosity and mobile entropy in vortex liquids
• T-square dependence of the electronic thermal resistivity in metallic strontium titanate
• Effects of spin-orbit interaction and electron correlations in strontium titanate
• Precision measurements of the AC field dependence of the superconducting transition in strontium titanate
• Ferroelectricity-induced multiorbital odd-frequency superconductivity in SrTiO${}_3$
• A local maximum in the superconducting transition temperature of Nb-doped strontium titanate under uniaxial compressive stress
• Strain-engineered interaction of quantum polar and superconducting phases