Europhys. Lett.
Volume 66, Number 6, June 2004
Page(s) 840 - 846
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 June 2004
Europhys. Lett., 66 (6) , pp. 840-846 (2004)
DOI: 10.1209/epl/i2003-10265-1

Unusual interplay between copper-spin and vortex dynamics in slightly overdoped $\chem{La_{1.83}Sr_{0.17}CuO_4}$

R. Gilardi1, A. Hiess2, N. Momono3, M. Oda3, M. Ido3 and J. Mesot1

1  Laboratory for Neutron Scattering, ETH Zurich and PSI Villigen CH-5232 Villigen, Switzerland
2  Institute Laue-Langevin - BP 156, F-38042 Grenoble Cedex, France
3  Department of Physics, Hokkaido University - Sapporo 060-0810, Japan

(Received 10 October 2003; accepted in final form 19 April 2004)

Our inelastic neutron scattering experiments of the spin excitations in the slightly overdoped $\chem{La_{1.83}Sr_{0.17}CuO_4}$ compound show that, under the application of a magnetic field of 5 tesla, the low-temperature susceptibility undergoes a weight redistribution centered at the spin gap energy. Furthermore, by comparing the temperature dependence of the neutron data with ac susceptibility and magnetization measurements, we conclude that the filling-in of the spin gap tracks the irreversibility/melting temperature rather than $T_{\ab{c2}}$, which indicates an unusual interplay between the magnetic vortices and the spin excitations even in the slightly overdoped regime of high-temperature superconductors.

74.72.Dn - $\chem{La}$-based cuprates.
25.40.Fq - Inelastic neutron scattering.
75.40.Gb - Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.).

© EDP Sciences 2004