0000000000594267
AUTHOR
J. B. Parkinson
showing 2 related works from this author
Small clusters with Heisenberg antiferromagnetic exchange
2000
We study small symmetrical clusters of magnetic ions with Heisenberg antiferromagnetic exchange interaction. We calculate the magnetization and the specific heat as functions of applied magnetic field at zero and non-zero temperature. Results are given for both classical and quantum systems. At zero temperature the classical systems undergo a series of transitions where the symmetry changes as a function of applied field. The quantum systems show similar features to Ising systems previously studied.
Small clusters with anisotropic antiferromagnetic exchange in a magnetic field
2004
We consider small symmetric clusters of magnetic atoms (spins) with anisotropic exchange interaction between the atoms in a magnetic field at zero temperature. The inclusion of the anisotropy leads to a wealth of different phases as a function of the applied magnetic field. These are not phases in the thermodynamic sense with critical properties but rather physical structures with different arrangements of the spins and hence different symmetries. We study the spatial symmetry of these phases, for the classical and quantum cases. Results are presented mainly for three frustrated systems, the triangle, the tetrahedron and the five-atom ring, which have many interesting features. In the class…