Influence of gap structures to specific heat in oriented magnetic fields: Application to the orbital dependent superconductor, Sr${}_2$RuO${}_4$

Abstract

We discuss influence of modulation of gap function and anisotropy of Fermi velocity to field angle dependences of upper critical field, $H_{c2}$, and specific heat, $C$, on the basis of the approximate analytic solution in the quasiclassical formalism. Using 4-fold modulation of the gap function and the Fermi velocity in the single-band model, we demonstrate field and temperature dependence of oscillatory amplitude of $H_{c2}$ and $C$. We apply the method to the effective two-band model to discuss the gap structure of Sr${}_2$RuO${}_4$, focusing on recent field angle-resolved experiments. It is shown that the gap structures with the intermediate magnitude of minima in $[100]$ direction for $\gamma$ band, and tiny minima of gaps in $[110]$ directions for $\alpha$ and $\beta$ bands give consistent behaviors with experiments. The interplay of the above two gaps also explains the anomalous temperature dependence of in-plane $H_{c2}$ anisotropy, where the opposite contribution from the passive $\alpha \beta$ band is pronounced near $T_c$.

7 pages, 11 figures in JPSJ format

References in corpus (4)

• Ginzburg-Landau theory of vortices in a multi-gap superconductor
• Gap Structure of the Spin-Triplet Superconductor Sr2RuO4 Determined from the Field-Orientation Dependence of Specific Heat
• Determination of the Superconducting Gap Structure in All Bands of the Spin-Triplet Superconductor Sr2RuO4
• Orientational field-dependence of low-lying excitations in mixed state of unconventional superconductors

Cited by in corpus (8)

• Evaluation of Spin-Triplet Superconductivity in Sr2RuO4
• Nodal Structure of Unconventional Superconductors Probed by the Angle Resolved Thermal Transport Measurements
• Angular dependence of the upper critical field of Sr2RuO4
• Theory of Transport Properties in the p-wave Superconducting State of Sr2RuO4 - A Microscopic Determination of the Gap Structure -
• Quasi-classical determination of the in-plane magnetic field phase diagram of superconducting Sr_2RuO_4
• Impurity Effect on Kramer-Pesch Core Shrinkage in s-Wave Vortex and Chiral p-Wave Vortex
• Anisotropy of in-plane magnetization due to nodal gap structure in the vortex state
• Analysis of field-angle dependent specific heat in unconventional superconductors: a comparison between Doppler-shift method and Kramer-Pesch approximation