Specific heat and thermal conductivity in the mixed state of MgB2
arXiv:cond-mat/0204468 · doi:10.1103/PhysRevLett.89.137003
Abstract
The specific heat C and the electronic and phononic thermal conductivities kappa_e and kappa_{ph} are calculated in the mixed state for magnetic fields H near H_{c2}. The effects of supercurrent flow and Andreev scattering of the Abrikosov vortex lattice on the quasiparticles are taken into account. The resulting function C(H) is nearly linear while kappa_e(H) exhibits an upward curvature near H_{c2}. The slopes decrease with impurity scattering which improves the agreement with the data on MgB_2. The ratio of phonon relaxation times tau_n/tau_s = g(omega_0,H) for phonon energy omega_0, which is nearly a step function at omega_0 = 2Delta for the BCS state, is smeared out and tends to one for increasing H. This leads to a rapid reduction of kappa_{ph}(H) in MgB_2 for relatively small fields due to the rapid suppression of the smaller energy gap.
8 pages, 4 figures, accepted for publication in Phys. Rev. Letters
References in corpus (4)
- Order parameter of MgB_2: a fully gapped superconductor
- Field Dependence of Electronic Specific Heat in Two-Band Superconductors
- Thermal Conductivity near H_c2 for spin-triplet superconducting States with line nodes in Sr_2RuO_4
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Cited by in corpus (4)
- Influence of carbon substitution on the heat transport in single crystalline MgB2
- Thermal conductivity of Al-doped MgB2: Impurity scattering and the validity of the Wiedemann-Franz law
- Specific heat and thermal conductivity in the vortex state of the two-gap superconductor MgB_2
- Orbital-dependent two-band superconductivity in MgB2