En. Junior et al., INSTABILITIES AND REPLICA-SYMMETRY BREAKING IN THE 4-STATE CLOCK SPIN-GLASS, Journal of physics. A, mathematical and general, 27(13), 1994, pp. 4369-4377
The infinite-range four-state clock spin glass, in the presence of an
arbitrary magnetic field, is investigated by the replica method. The a
ppropriate replica-symmetry breaking scheme is discussed for this mode
l. It is shown that two distinct Almeida-Thouless lines are possible,
depending on the direction of the applied field. The full phase diagra
m of the model, showing its instability regions, is presented and disc
ussed.