Open AccessMagnetic correlations in a classic Mott system
Author(s) -
Wei Bao,
C. Broholm,
G. Aeppli,
S. A. Carter,
David Yun Dai,
C. D. Frost,
J. M. Honig,
P. Metcalf
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/672105
Subject(s) - antiferromagnetism , condensed matter physics , magnetism , degenerate energy levels , metal–insulator transition , fermi surface , paramagnetism , physics , mott insulator , spin (aerodynamics) , electrical resistivity and conductivity , quantum mechanics , superconductivity , thermodynamics
The metal-insulator transition in V{sub 2}O{sub 3} causes a fundamental change in its magnetism. While the antiferromagnetic insulator (AFI) is a Heisenberg localized spin system, the antiferromagnetism in the strongly correlated metal is determined by a Fermi surface instability. Paramagnetic fluctuations in the metal and insulator represent similar spatial spin correlations, but are unrelated to the long range order in the AFI. The phase transition to the AFI induces an abrupt switching of magnetic correlations to a different magnetic wave vector. The AFI transition, therefore, is not a conventional spin order-disorder transition. Instead it is accounted for by an ordering in the occupation of the two degenerate d-orbitals at the Fermi level