Simultaneous evidence for Pauli paramagnetic effects and multiband superconductivity in KFe2As2 by small-angle neutron scattering studies of the vortex lattice

S. J. Kuhn; H. Kawano-Furukawa; E. Jellyman; R. Riyat; E. M. Forgan; M. Ono; K. Kihou; C. H. Lee; F. Hardy; P. Adelmann; Th. Wolf; C. Meingast; J. Gavilano; M. R. Eskildsen

doi:10.1103/PhysRevB.93.104527

Simultaneous evidence for Pauli paramagnetic effects and multiband superconductivity in KFe2As2 by small-angle neutron scattering studies of the vortex lattice

S. J. Kuhn, H. Kawano-Furukawa, E. Jellyman, R. Riyat, E. M. Forgan, M. Ono, K. Kihou, C. H. Lee, F. Hardy, P. Adelmann, Th. Wolf, C. Meingast, J. Gavilano, M. R. Eskildsen

DOI 10.1103/PhysRevB.93.104527 · Physical Review B

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Abstract

We study the intrinsic anisotropy of the superconducting state in KFe2As2 by using small-angle neutron scattering to image the vortex lattice as the applied magnetic field is rotated towards the FeAs crystalline planes. The anisotropy is found to be strongly field dependent, indicating multiband superconductivity. Furthermore, the high-field anisotropy significantly exceeds that of the upper critical field, providing further support for Pauli limiting in KFe2As2 for fields applied in the basal plane. The effect of Pauli paramagnetism on the unpaired quasiparticles in the vortex cores is directly evident from the ratio of scattered intensities due to the longitudinal and transverse vortex lattice field modulation.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
KFe2As2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	3.4	Pressure not reported	unknown