Quantum spin dynamics

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Fermi surface spectroscopy: a magnetic resonance approach

PHYSICA B 280:1-4 (2000) 281-282

Authors:

JM Schrama, SO Hill, J Singleton, A Ardavan, E Rzepniewski, R Edwards

Abstract:

We describe recently-developed GHz magneto-optical techniques which measure the Fermi-surface topologies and superconducting order parameter symmetry in organic molecular metals. (C) 2000 Elsevier Science B.V. All rights reserved.

Halides of BET-TTF: Novel hydrated molecular metals

Advanced Materials 12:1 (2000) 54-58

Authors:

E Laukhina, E Ribera, J Vidal-Gancedo, S Khasanov, L Zorina, R Shibaeva, E Canadell, V Laukhin, M Honold, MS Nam, J Singleton, J Veciana, C Rovira

Abstract:

A new family of hydrated molecular metals based on the bis(ethylenethio- tetrathiafulvalene) (BET-TTF) donor was developed. A metal stable down to 0.5 K was obtained for the first time from this donor, perhaps due to the absence of disorder in the peripheral sulfur atoms. A hint of superconducting transition in some crystals of the BET-TTF2Br·3H2O salt was observed.

Observation of the Fulde-Ferrell-Larkin-Ovchinnikov state in the quasi-two-dimensional organic superconductor k-(BEDT-TTF)2Cu(NCS)2 (BEDT-TTF bis(ethylene-dithio)tetrathiafulvalene)

JOURNAL OF PHYSICS-CONDENSED MATTER 12:40 (2000) L641-L648

Authors:

J Singleton, JA Symington, MS Nam, A Ardavan, M Kurmoo, P Day

Angle dependence of the upper critical field in the layered organic superconductor kappa-(BEDT-TTF)2Cu(NCS)2 (BEDT-TTFequiv bis(ethylene-dithio)tetrathiafulvalene)

Journal of Physics Condensed Matter IOP Publishing 11:43 (1999) l477

Authors:

M-S Nam, JA Symington, J Singleton, SJ Blundell, A Ardavan, JAAJ Perenboom, M Kurmoo, P Day

Angle dependence of the upper critical field in the layered organic superconductor κ-(BEDT-TTF)2Cu(NCS)2 (BEDT-TTF ≡ bis(ethylene-dithio)tetrathiafulvalene)

Journal of Physics Condensed Matter 11:43 (1999)

Authors:

MS Nam, JA Symington, J Singleton, SJ Blundell, A Ardavan, JAAJ Perenboom, M Kurmoo, P Day

Abstract:

We have performed detailed studies of the angle- and temperature-dependent resistive upper critical fields in the layered organic superconductor κ-(BEDT-TTF)2Cu(NCS)2. With the magnetic field lying in the conducting planes, our measurements show an upper critical field which comfortably exceeds the Pauli-paramagnetic limit in this material. We find no azimuthal angle dependence of the critical field, in spite of recent evidence that this material has gap nodes characteristic of d-wave superconductivity. We propose that the large critical fields may be due to a Fulde-Ferrell-Larkin-Ovchinnikov state which can exist in exactly in-plane fields because of the nature of the Fermi surface of κ-(BEDT-TTF)2Cu(NCS)2. © 1999 IOP Publishing Ltd.