Correlation length in cuprates deduced from the impurity-induced magnetization

S. Ouazi (1) , J. Bobroff (1) , H. Alloul (1) , W. A. Macfarlane (1)

1 LPS - Laboratoire de Physique des Solides

We report a new multi-nuclei based NMR method which allows us to image the staggered polarization induced by nonmagnetic Li impurities in underdoped O6.6 and slightly overdoped O7 YBa2Cu3O6+y above T_C. The spatial extension of the polarization xi_imp approximately follows a Curie law, increasing up to six lattice constants at T=80K at O6.6 in the pseudogap regime. Near optimal doping, the staggered magnetization has the same shape, with xi_imp reduced by a factor 2. xi_imp is argued to reveal the intrinsic magnetic correlation length of the pure system. It is found to display a smooth evolution through the pseudogap regime.

Domaines: Supraconductivité [cond-mat.supr-con]

S. Ouazi, J. Bobroff, H. Alloul, W. A. Macfarlane. Correlation length in cuprates deduced from the impurity-induced magnetization. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2004, 70, pp.104515. ⟨hal-00138265⟩