8,506 research outputs found
Magnetic penetration depth in disordered iron-based superconductors
We study the effect of disorder on the London penetration depth in iron-based
superconductors. The theory is based on a two-band model with
quasi-two-dimensional Fermi surfaces, which allows for the coexistence region
in the phase diagram between magnetic and superconducting states in the
presence of intraband and interband scattering. Within the quasiclassical
approximation we derive and solve Eilenberger's equations, which include a weak
external magnetic field, and provide analytical expressions for the penetration
depth in the various limiting cases. A complete numerical analysis of the
doping and temperature dependence of the London penetration depth reveals the
crucial effect of disorder scattering, which is especially pronounced in the
coexistence phase. The experimental implications of our results are discussed.Comment: 10 pages, 6 figure
Transport implications of Fermi arcs in the pseudogap phase of the cuprates
We derive the fermionic contribution to the longitudinal and Hall
conductivities within a Kubo formalism, using a phenomenological Greens
function which has been previously developed to describe photoemission data in
the pseudogap phase of the cuprates. We find that the in-plane electrical and
thermal conductivities are metallic-like, showing a universal limit behavior
characteristic of a d-wave spectrum as the scattering rate goes to zero. In
contrast, the c-axis resistivity and the Hall number are insulating-like, being
divergent in the same limit. The relation of these results to transport data in
the pseudogap phase is discussed.Comment: 3 pages, 2 figure
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