Test for Interlayer Coherence in a Quasi-Two-Dimensional Superconductor

John Singleton; P. A. Goddard; A. Ardavan; N. Harrison; S. J. Blundell; J. A. Schlueter; A. M. Kini

doi:10.1103/PhysRevLett.88.037001

Test for Interlayer Coherence in a Quasi-Two-Dimensional Superconductor

John Singleton, P. A. Goddard, A. Ardavan, N. Harrison, S. J. Blundell, J. A. Schlueter, and A. M. Kini

Phys. Rev. Lett. 88, 037001 – Published 2 January 2002

Abstract

Peaks in the magnetoresistivity of the layered superconductor $κ - (BEDT - TTF)_{2} Cu (NCS)_{2}$ , measured in fields $\leq 45 T$ applied within the layers, show that the Fermi surface is extended in the interlayer direction and enable the interlayer transfer integral $(t_{⊥} \approx 0.04 meV)$ to be deduced. However, the quasiparticle scattering rate $τ^{- 1}$ is such that $ħ / τ \sim {6 t}_{⊥}$ , implying that $κ - (BEDT - TTF)_{2} Cu (NCS)_{2}$ meets the criterion used to identify interlayer incoherence. The applicability of this criterion to anisotropic materials is thus shown to be questionable.

Received 30 April 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.037001

Authors & Affiliations

John Singleton^1,2, P. A. Goddard², A. Ardavan², N. Harrison¹, S. J. Blundell², J. A. Schlueter³, and A. M. Kini³

¹National High Magnetic Field Laboratory, LANL, MS-E536, Los Alamos, New Mexico 87545
²Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
³Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439