Publications
Martin Greven
Quantum Impurities in the Two-dimensional Spin One-half Heisenberg AntiferromagnetO. P. Vajk, P. K. Mang, M. Greven, P. M. Gehring, J. W. Lynn, Science 295, 1691 (2002)
Download from http://www.sciencemag.org/cgi/content/abstract/295/5560/1691
Abstract
The study of randomness in low-dimensional quantum antiferromagnets is at the forefront of research in the field of strongly correlated electron systems, yet there have been relatively few experimental model systems. Complementary neutron scattering and numerical experiments demonstrate that the spin-diluted Heisenberg antiferromagnet La2Cu1-z(Zn,Mg)zO4 is an excellent model material for square-lattice site percolation in the extreme quantum limit of spin one-half. Measurements of the ordered moment and spin correlations provide important quantitative information for tests of theories for this complex quantum-impurity problem.