Spinon excitation in spatially anisotropic frustrated Heisenberg models

A. Benyoussef, Abdelrhani Boubekri, Hamid Ez-zahraouy A

G. G. Cabrera, Maximiliano Montenegro, C. Millán +1 more

L.S. Lima

J. Ricardo de Sousa

Masanori Kohno

Dynamical properties of frustrated XXZ models in the Ising limit on spatially anisotropic two-dimensional lattices are investigated by a weak-coupling approach from the one-dimensional limit. Restricting the Hilbert space to that spanned by exact eigenstates of XXZ chains in the Ising limit, we calculate dynamical structure factor 5 -+ (k,ω) in spatially anisotropic two-dimensional systems. As in the case of frustrated Heisenberg models [M.Kohno, et al. , Nat. Phys. 3, 790 (2007)], spinons form bound states through hopping process between chains. We calculate the density-density correlation function of spinons in the Ising limit, and show that spinons in the bound state hop together as a pair, although those in a continuous spectrum behave almost independently. We discuss possible implications of the present results on fractionalization of bosonic and fermionic particles in spatially anisotropic frustrated systems with strong repulsion.

S C Y Siak, M W Long

In this paper, the authors discuss a class of quasi-one-dimensional models containing both spins and charge, which share the same generic solutions. In particular, they concentrate on a Heisenberg model of a topologically frustrated antiferromagnet, and a d-p model for oxygen hole hopping in a subgeometry of the copper-oxygen plane of the perovskite superconductors. The outstanding feature of these models lies in the simplicity of their solutions: their ground states are exact and contain uncorrelated, short-ranged singlet pairs. Excitations in these models fall into two distinct classes, namely, spin-1/2 chargeless domain-wall excitations or 'spinons', together with their conjugate excitations, which take the form of spin-1/2 chargeless 'antispinon' domain walls in the Heisenberg model, and spinless charge+e hole excitations or 'holons' in the d-p model. In the case of the Heisenberg model, the authors have successfully constructed a sufficiently simple representation for the 'spinon' excitation which allows them to calculate its dispersion using elementary methods. This is therefore a concrete example of a 'spinon' excitation for which explicit representation has been possible.