Z. Domanski, COMPETITION BETWEEN AXIAL AND CUBIC ANISOTROPIES IN HEISENBERG SPIN-GLASSES, Physical review. B, Condensed matter, 55(9), 1997, pp. 5827-5832
An infinite-range quantum Heisenberg spin glass with uniaxial (D) and
cubic (K) anisotropies is studied using the thermo-held-dynamic method
. Mean-field theory phase diagrams in the temperature-anisotropy plane
(T,D) for quantum spins S = 2 and S = 5/2 are presented for different
values of K. Generally, for integer spin values and large anisotropy
D a condensation into a nonmagnetic spin state occurs, accompanied by
the destruction of the spin-glass order as indicated by the finite cri
tical value D-c(T=0). For half-integer S and sufficiently low temperat
ure, the spin-glass phase persists for arbitrary D and K. In both case
s the presence of a cubic term induces complicated crossovers from lon
gitudinal to transverse freezing of spins.