SPIN STRUCTURE AROUND MOBILE HOLES IN AN ANTIFERROMAGNET

A hole in the two-dimensional antiferromagnetic state moves coherently resonating with the quantum spin fluctuation and is accompanied by distortions in the local spin structure around it like a magnetic polaron which extends up to third near neighbour sites. Spin correlation functions suggest a twisted character of the distortion. Due to the spin distortion around a hole, new spectra of the optical conductivity and Raman scattering of two-magnon process appear in the mid-infrared region. There also appear spectra of A1g symmetry in Raman spectra which are prohibited in the insulating state. These results are consistent with the experimental ones. © 1990, Elsevier Science Publishers B.V. (North-Holland). All rights reserved.