Multiband character of $\beta$-FeSe: Angular dependence of the magnetoresistance and upper critical field

Abstract

We studied $ab$-plane transport properties in single crystals of the superconductor $\beta$-FeSe up to 16 T. In the normal state, below 90 K, the crystals present a strongly anisotropic positive magnetoresistance that becomes negligible above that temperature. In the superconducting state (T${}_c$=8.87(5) K) the upper critical field anisotropy $H$${}_{c2}$$\parallel$$ab$ / $H$${}_{c2}$$\parallel$$c$ changes with temperature and the angular dependence of the dissipation for fixed temperatures and fields reflects a strongly anisotropic behavior. Our results make evident that multiband effects are needed to describe the measured transport properties. We model the magnetoresistance and upper critical field behavior with a two-band model showing that the diffusivities ratio parameter remains unchanged going from the normal to the superconducting state.

5 pages, 4 figures, 27th International Conference on Low Temperature Physics (LT27)

References in corpus (4)

• Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)
• The Structural Phase Transition in FeSe (Fe1+dSe)
• Upper critical fields and thermally-activated transport of Nd(O_0.7F_0.3)FeAs single crystal
• Multiband effects on beta-FeSe single crystals

Cited by in corpus (4)

• Anisotropic type-I superconductivity and anomalous superfluid density in OsB 2
• Disordered hyperuniform vortex matter with rhombic distortions in FeSe at low fields
• Vortex dynamics in $\beta$-FeSe single crystals: effects of proton irradiation and small inhomogeneous stress
• Impact of atomic defects in the electronic states of FeSe${}_{1-x}$S${}_x$ superconducting crystals