Field-Induced Metal-Insulator Transition in a Two-Dimensional Organic Superconductor

J. Wosnitza; S. Wanka; J. Hagel; H. v. Löhneysen; J. S. Qualls; J. S. Brooks; E. Balthes; J. A. Schlueter; U. Geiser; J. Mohtasham; R. W. Winter; G. L. Gard

doi:10.1103/PhysRevLett.86.508

Field-Induced Metal-Insulator Transition in a Two-Dimensional Organic Superconductor

J. Wosnitza, S. Wanka, J. Hagel, H. v. Löhneysen, J. S. Qualls, J. S. Brooks, E. Balthes, J. A. Schlueter, U. Geiser, J. Mohtasham, R. W. Winter, and G. L. Gard

Phys. Rev. Lett. 86, 508 – Published 15 January 2001

Abstract

The quasi-two-dimensional organic superconductor $β^{''} - (BEDT - TTF)_{2} {SF}_{5} {CH}_{2} {CF}_{2} {SO}_{3}$ $(T_{c} \approx 4.4 K)$ shows very strong Shubnikov–de Haas (SdH) oscillations which are superimposed on a highly anomalous steady background magnetoresistance, $R_{b}$ . Comparison with de Haas–van Alphen oscillations allows a reliable estimate of $R_{b}$ which is crucial for the correct extraction of the SdH signal. At low temperatures and high magnetic fields insulating behavior evolves. The magnetoresistance data violate Kohler's rule, i.e., cannot be described within the framework of semiclassical transport theory, but converge onto a universal curve appropriate for dynamical scaling at a metal-insulator transition.

Received 8 June 2000

DOI:https://doi.org/10.1103/PhysRevLett.86.508

Authors & Affiliations

J. Wosnitza¹, S. Wanka¹, J. Hagel¹, H. v. Löhneysen¹, J. S. Qualls^2,*, J. S. Brooks², E. Balthes³, J. A. Schlueter⁴, U. Geiser⁴, J. Mohtasham⁵, R. W. Winter⁵, and G. L. Gard⁵

¹Physikalisches Institut, Universität Karlsruhe, D-76128 Karlsruhe, Germany
²National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306
³Grenoble High Magnetic Field Laboratory, MPI-Festkörperforschung and C.N.R.S., F-38042 Grenoble, France
⁴Chemistry and Materials Science Divisions, Argonne National Laboratory, Argonne, Illinois 60439
⁵Department of Chemistry, Portland State University, Portland, Oregon 97207