Ring Exchange and Correlated Fermions
Strongly Correlated Electrons
2009-11-11 v1 Superconductivity
Abstract
The concept of exchange in strongly-correlated fermions is reviewed with emphasis on the generalization of the Heisenberg pair exchange to higher order n-particle permutations. The "frustration" resulting from competing ferromagnetic three-spin exchange and antiferromagnetic two- and four-spin exchanges is illustrated on a two-dimensional model system: solid 3He films. Recent experimental results proving the presence of four-spin exchange interactions in the CuO2 plaquettes of high Tc cuprates are reported.
Keywords
Cite
@article{arxiv.cond-mat/0504141,
title = {Ring Exchange and Correlated Fermions},
author = {Michel Roger},
journal= {arXiv preprint arXiv:cond-mat/0504141},
year = {2009}
}
Comments
Invited talk at ISSP9 Conference Tokyo, Japan, November 2004 10 pages