Inhomogeneous Spin Chain Research Articles

Solutions to the reflection equation and integrable systems for N = 2 SQCD with classical groups

Integrable systems underlying the Seiberg-Witten solutions for the N = 2 SQCD with gauge groups SO( n) and Sp( n) are proposed. They are described by the inhomogeneous XXX spin chain with specific boundary conditions given by reflection matrices. We attribute reflection matrices to orientifold planes in the brane construction and briefly discuss its possible deformations.

Nonlinear spin-phonon excitations in an inhomogeneous compressible biquadratic Heisenberg spin chain

We consider an inhomogeneous compressible biquadratic Heisenberg ferromagnetic spin chain with harmonic and anharmonic lattice vibrations in the classical continuum limit and identify integrable soliton models. Also, we present some simple localized (one- and twosoliton-like) spin-phonon excitations.

Surface-embeddability approach to the dynamics of the inhomogeneous Heisenberg spin chain

The surface-embeddability approach of Lund and Regge is applied to the classical, inhomogeneous Heisenberg spin chain to study the class of inhomogeneity functions f for which the spin evolution equation and its gauge-equivalent generalized nonlinear Schrödinger equation (GNLSE) are exactly solvable. Writing the spin vector S(x,t) as ∂xr and identifying r(x,t) with a position vector generating a surface, we show that the kinematic equation satisfied by r implies certain constraints on the admissible geometries of this surface. These constraints, together with the Gauss–Mainardi–Codazzi equations, enable us to express the coefficient of the second fundamental form as well as f in terms of the metric coefficients G and its derivatives, for arbitrary time-independent G. Explicit solutions for the GNLSE can also be found in terms of the same quantities. Of the admissible surfaces generated by r, a special class that emerges naturally is that of surfaces of revolution: Explicit solutions for r and S are found and discussed for this class of surfaces.

Dynamics of an inhomogeneous anisotropic antiferromagnetic spin chain

AbstractNonlinear spin excitations in the two‐sublattice model of a one‐dimensional classical continuum Heisenberg inhomogeneous antiferromagnetic spin chain are investigated. The dynamics of the inhomogeneous chain reduces to that of its homogeneous counterpart when the inhomogeneity assumes a particular form. Apart from the twists, some planar configurations representing the nonlinear dynamics of spins are obtained.

Dual properties of lattice systems with broken symmetry: Ising and potts chains in an external field

Dual transformation that produces a path between inhomogeneous spin chains in a site-dependent potential and inhomogeneous spin chains with nonconstant interactions is established. It implies coupling of equivalent random versions of theoretical models. The duality is observed for a number of spin chains with nearest-neighbour as well as multispin interactions.