s=12antiferromagnetic Heisenberg model on fullerene-type symmetry clusters

antiferromagnetic Heisenberg model on fullerene - type symmetry clusters

The si= 1 2 nearest-neighbor antiferromagnetic Heisenberg model is considered for spins sitting on the vertices of clusters with the connectivity of fullerene molecules and a number of sites n ranging from 24 to 32. Using the permutational and spin-inversion symmetries of the Hamiltonian, the low-energy spectrum is calculated for all the irreducible representations of the symmetry group of each...

Symmetry of Fullerene C_60

Unconventional magnetic properties of the icosahedral symmetry antiferromagnetic Heisenberg model

The antiferromagnetic Heisenberg model on icosahedral symmetry Ih fullerene clusters exhibits unconventional magnetic properties despite the lack of anisotropic interactions. At the classical level, and for number of sites n 720, the magnetization has two discontinuities in an external magnetic field, except from the dodecahedron where it has three, emphasizing the role of frustration introduce...

Nitride clusters in fullerene cages

focus of fundamental and applied materials research since the first preparation of macroscopic C60 quantities by Krätschmer et al. in 1990 [1]. The ability to encage atoms and small molecules opened the door to new structures which are highly reactive under standard conditions. Up to now low production yields and a time consuming multi stage separation hampered the search for applications of en...

Symmetry considerations on the magnetization process of the Heisenberg model on the pyrochlore lattice

Abstract. We present a detailed symmetry analysis of the degeneracy lifting due to higher order spin exchanges in the pyrochlore lattice in applied magnetic field. Under the assumption of the 4 sublattice ordering, the criteria for a stable half-magnetization plateau are deduced. The higher order exchange terms may originate from spin–lattice coupling, or can describe quantum and thermal fluctu...