Eur. Phys. J. B 3, 163-167 (1998)
https://doi.org/10.1007/s100510050297

New slow and short range magnetic correlations in superconducting _a2_xSxCuO₄

Laboratoire Léon Brillouin, CE-SACLAY, 91191 Gif-sur-Yvette, France and Laboratoire de Chimie des solides (URA 446 CNRS) , Université Paris-Sud, Orsay, France

Corresponding author: ^a spetit@bali.saclay.cea.fr

Received: 3 September 1997
Revised: 21 November 1997
Accepted: 26 January 1998
Published online: 15 May 1998

Abstract

Inelastic neutron scattering measurements have been performed on high quality single crystals of in order to study the spin dynamics of this compound. In addition to the well-established incommensurate magnetic response, we show the existence of a new set of low energy excitations present in the whole superconducting region of the phase diagram. This new feature of the dynamical cross section is characterized, below about 10 K, by very short range ( lattice spacing) antiferromagnetic correlations and by a low energy scale of meV. At higher temperatures these fluctuations become nearly Q-independent. Different possible origins of these new spin correlations are discussed.