title: Critical spin dynamics of the 2D quantum Heisenberg antiferromagnets Sr2CuO2Cl2 and Sr2Cu3O4Cl2.
abstract: We report a neutron scattering study of the long-wavelength dynamic spin correlations in the model two-dimensional S = 1/2 square lattice Heisenberg antiferromagnets Sr2CuO2Cl2 and Sr2Cu3O4Cl2. The characteristic energy scale, omega(0)(T/J), is determined by measuring the quasielastic peak width in the paramagnetic phase over a wide range of temperature ( 0.2 less similarT/J less similar0.7). The obtained values for omega(0)(T/J) agree quantitatively between the two compounds and also with values deduced from quantum Monte Carlo simulations. The combined data show scaling behavior, omega approximately xi(-z), over the entire temperature range with z = 1.0(1), in agreement with dynamic scaling theory.
authors: Department of Physics and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge 02139, USA.
authors: Y J
authors: YJ
authors: Kim
authors: R J
authors: RJ
authors: Birgeneau
authors: F C
authors: FC
authors: Chou
authors: R W
authors: RW
authors: Erwin
authors: M A
authors: MA
authors: Kastner