Inelastic neutron-scattering measurements of incommensurate magnetic excitations on superconducting LiFeAs single crystals.

Research paper by N N Qureshi, P P Steffens, Y Y Drees, A C AC Komarek, D D Lamago, Y Y Sidis, L L Harnagea, H-J HJ Grafe, S S Wurmehl, B B Büchner, M M Braden

Indexed on: 01 May '12Published on: 01 May '12Published in: Physical review letters


Magnetic correlations in superconducting LiFeAs were studied by elastic and by inelastic neutron-scattering experiments. There is no indication for static magnetic ordering, but inelastic correlations appear at the incommensurate wave vector (0.5±δ,0.5-/+δ,0) with δ~0.07 slightly shifted from the commensurate ordering observed in other FeAs-based compounds. The incommensurate magnetic excitations respond to the opening of the superconducting gap by a transfer of spectral weight.