Dresden 2014 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 30: Superconductivity - Poster Session
TT 30.10: Poster
Montag, 31. März 2014, 15:00–19:00, P2
Magneto-acoustic quantum oscillations in YNi2B2C — J. Nössler1, •S. Yasin1, S. Erfanifam1, R. Seerig1, G. Behr2, S. Zherlitsyn1, and J. Wosnitza1 — 1Hochfeld-Magnetlabor Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany — 2Leibniz-Institut für Festkörper- und Werkstoffforschung, D-01069 Dresden, Germany
Magneto-acoustic quantum oscillations in the type-II superconductor YNi2B2C (Tc=15.5 K) have been investigated providing information about the effective mass and Dingle temperature for selected electron orbits. Remarkably, the quantum oscillations in the sound velocity have been observed not only in the normal state but even below the upper critical field, Bc2 = 8.2 T, down to 3.6 T. Torque measurements performed with the same sample have revealed a complete suppression of the dHvA oscillations below Bc2. The marginal additional damping of the acoustic oscillations observed in the mixed state suggests that the corresponding electron band does not contribute to the superconductivity. This additional damping can be ascribed to the field inhomogeneity in the Shubnikov phase. Angular dependent ultrasound experiments in static (up to 18 T) and pulsed (up to 61 T) magnetic fields applied in the (010) plane have revealed four frequencies observed as well in earlier torque measurements and predicted from band-structure calculations. A new unknown frequency of 6756 T has been resolved from the pulsed-field ultrasound experiments.