Low-temperature magnetic properties of a Heisenberg model consisting of ferro- and antiferromagnetic layer superlattices are studied by using spin-wave theory and retarded Green's function method. The four-sublattice magnetizations and internal energy and specific heat at low temperature are...

The method of the effective-field theory with self-spin correlations and the differential operator technique is used to study the magnetic properties of the spin-3/2 Ising model with biaxial crystal-field on the honeycomb lattice. The effects of a biaxial crystal-field described by two uniaxial...

Magnetic properties of a biaxial spin system on the honeycomb and square lattice have been studied based on the effective-field theory with the differential operator technique. The effects of the external longitudinal magnetic field on the magnetization and susceptibility are discussed in...

The mixed spin-12 and spin-32 transverse Ising model with a crystal field is studied within the framework of the effective-field theory with correlations. The phase diagrams and thermal behaviors of magnetizations are investigated numerically for the honeycomb (z=3). The results show that there...

The mixed spin- 1/2 and spin- 3/2 transverse Ising model in a longitudinal magnetic field is studied within the framework of the effective-field theory with correlations. In this approach the effective-field equations are derived by using a probability distribution method based on the...

In this paper, we develop heterogeneous agent models with equilibrium unemployment to study the optimal taxation and labour wedge. We find that the the presence of profits plays an important role in the determination of both optimal tax policy and labour wedge. Judd-Chamley optimal zero capital...

Using a Mortensen-Pissarides search-and-matching framework, this paper investigates the importance of search frictions in determining the welfare and distributional effects of tax reforms that re-allocate the tax burden from capital to labour income. Calibrating the model to the UK economy, we...