The work at Karlsruhe was supported by the DFG. Work at Argonne National Laboratory was supported by the U.S. Dept. of Energy under Contract No. W-31-109-ENG-38. Work at Portland State University was supported by NSF Grant No. Che- 9904316 and the Petroleum Research Fund No. ACS-PRF 34624-AC7.
Physical Review B
Organic superconductors, Organic superconductors -- Measurement
We report the observation of Shubnikov–de Haas (SdH) oscillations in the mixed state of the organic superconductor β″-(BEDT-TTF)₂SF₅CH₂CF₂SO₃ (Tc≈4.4K). At low temperatures the SdH oscillations persist clearly below the upper critical field Bc₂(0)≈3.6 T almost down to the field where the resistivity vanishes. Rather unusually, no additional damping of the SdH-signal amplitude — as well as of the de Haas–van Alphen amplitude — is observed in the superconducting state. This indicates that the damping in the vortex state of this quasi-two-dimensional superconductor is different in character to that observed for most three-dimensional materials.
Wosnitza, J., Wanka, S., Hagel, J., Häussler, R., Löhneysen, H. V., Schlueter, J. A., Geiser, U., Nixon, P. G., Winter, R. W., Gard, G. L.(2000). Shubnikov-de Haas effect in the superconducting state of an organic superconductor. Physical Review B, 62, 11973