https://doi.org/10.1140/epjb/e2011-20821-6
Regular Article
Detailed study of the de Haas-van Alphen effect in the Shubnikov state of LuNi2B2C
1
Hochfeld-Magnetlabor Dresden (HLD), Helmholtz-Zentrum
Dresden-Rossendorf, 01314
Dresden,
Germany
2
Leibniz-Institute for Solid State and Materials Research
(IFW-Dresden), 01171
Dresden,
Germany
3
Ames Laboratory and Department of Physics and Astronomy, Iowa
State University, Ames, 50011
Iowa,
USA
a
Present address: Dresden University of Technology, Institute for
Materials Science, Helmholtzstraße 7, 01069 Dresden, Germany. e-mail:
Beate.Bergk@tu-dresden.de
Received:
7
October
2011
Received in final form:
12
December
2011
Published online:
13
February
2012
We present de Haas-van Alphen (dHvA) measurements in the normal and in the superconducting state of LuNi2B2C. Inside the superconducting state, we observe quantum oscillations of a spherical Fermi-surface sheet in all crystallographic directions. Apart from the field region close to the phase transition where a strong peak effect hampers the analysis of the dHvA signal, the additional damping of the quantum oscillations inside the superconducting state is much smaller than expected from theory. For the magnetic field aligned along the [100] direction, three different dHvA frequencies are visible in the superconducting state. In particular, the orbit related to a cushion-like Fermi surface does not show any additional damping at and below the upper critical field contrary to theoretical expectations of simple effective one-band theories. Consequently, the superconducting gap on this Fermi-surface sheet can only evolve at lower fields than the observed bulk critical field, Bc2 ≈ 8 T, which clearly points to a Fermi-surface-sheet-dependent gap opening in LuNi2B2C.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2012