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arXiv · 1702.02811

Field-induced gapless electron pocket in the superconducting vortex phase of YNi2B2C as probed by magnetoacoustic quantum oscillations

J. Nössler·R. Seerig·S. Yasin·M. Uhlarz·S. Zherlitsyn·G. Behr·S. -L. Drechsler·G. Fuchs·H. Rosner·J. Wosnitza
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Abstract

By use of ultrasound studies we resolved magneto-acoustic quantum oscillation deep into the mixed state of the multiband nonmagnetic superconductor YNi2B2C. Below the upper critical field, only a very weak additional damping appears that can be well explained by the field inhomogeneity caused by the flux-line lattice in the mixed state. This is clear evidence for no or a vanishingly small gap for one of the bands, namely, the spheroidal alpha band. This contrasts de Haas--van Alphen data obtained by use of torque magnetometry for the same sample, with a rapidly vanishing oscillation signal in the mixed state. This points to a strongly distorted flux-line lattice in the latter case that, in general, can hamper a reliable extraction of gap parameters by use of such techniques.

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J. Nössler, R. Seerig, S. Yasin, M. Uhlarz, S. Zherlitsyn, G. Behr, S. -L. Drechsler, G. Fuchs, H. Rosner, J. Wosnitza. 2017-02-09. Field-induced gapless electron pocket in the superconducting vortex phase of YNi2B2C as probed by magnetoacoustic quantum oscillations. https://doi.org/10.1103/physrevb.95.014523

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