Spin-spin correlation lengths of bilayer antiferromagnets

¹ Department of Physics and Astronomy, University of California Los Angeles, CA 90095, USA
² Institute for Solid State Physics, University of Tokyo Roppongi 7-22-1, Minatoku, Tokyo 106, Japan

Received: 12 February 1998
Accepted: 17 April 1998

Abstract

The correlation length and the static structure factor for bilayer antiferromagnets, such as , are calculated using field theoretical and numerical methods. It is shown that these quantities can be directly measured in neutron scattering experiments using energy integrated two-axis scan despite the strong intensity modulation perpendicular to the layers. Our calculations show that the correlation length of the bilayer antiferromagnet diverges considerably more rapidly, as the temperature tends to zero, than the correlation length of the corresponding single-layer antiferromagnet typified by . This rapid divergence may have important consequences with respect to magnetic fluctuations of the doped superconductors.