Torque formula as sum in reciprocal lattice for anisotropic superconductors

Phase-Sensitive Flux-Flow resistivity in Unconventional Superconductors

“…Combined with our previous results for Γ (α M ) [6], the behavior of ρ f (α M ) can be understood as follows. In the line-node s-wave case, when the magnetic field is applied to the node direction, Γ (α M ) takes the minimum [6] while ρ f (α M ) due only to ω 0 (k F ) exhibits its maximum [ Fig. 2].…”

“…Here, y is the impact parameter, d(k F ) is the anisotropy factor of the pair potential, ∆ 0 is the maximum amplitude of the pair potential in the bulk, and v F⊥ is the FS average of |v F⊥ (k F )| defined in ref. [6]. In the quasiclassical approximation, the QP spectrum is continuous with respect to the impact parameter y [11].…”

“…in polar coordinates [6].â,b,ĉ are orthogonal unit vectors fixed to the crystal axes. Here, we have assumed an isotropic spherical FS.…”

“…Here, we have assumed an isotropic spherical FS. The angle α M indicates the direction of the applied magnetic field rotated in a plane perpendicular to the c axis [6], and it is measured from the φ k = 0 direction (â-axis direction). Γ n is the scattering rate in the normal state.…”

“…ε is the energy of the quasiparticle (QP) bound state inside a vortex core and T is the temperature. In a previous paper [6], we took into account only the QP scattering rate Γ (k F ) as a contribution to ρ f . Here, the Fermi wave number k F denotes the position on a Fermi surface (FS).…”