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A. G. Sedrakyan

Publications and source records attributed to A. G. Sedrakyan.

6 recordsLinked to original sources
arXiv2009

Characteristics of 2D lattice models from fermionic realization: Ising and $XYZ$ models

We develop a field theoretical approach to the classical two-dimensional models, particularly to 2D Ising model (2DIM) and $XYZ$ model, which is simple to apply for calculation of various correlation functions. We calculate the partition function of 2DIM and $XY$ model within the developed framework. Determinant representation of spin-spin correlation functions is derived using fermionic realization for the Boltzmann weights. The approach also allows formulation of the partition function of 2DIM in the presence of an external magnetic field.

cond-mat.str-el↗
arXiv2008

Next-nearest-neighbor spin-spin and chiral-spin correlation functions in generalized XXX chain

We develop a simple technique for calculation of next to nearest neighbor spin-spin and chiral-spin correlation functions in inhomogeneous XXX model. Exact expression of the chiral-spin order parameter as a function of the model parameter, $ω$, is analytically found. Using the same method we also calculate the next to nearest neighbor spin-spin correlation function. In the limit $ω-> 0$ it reproduces the known result for the vacuum expectation value of the next to nearest neighbor spins in the standard Heisenberg spin chain. The technique is simple and can be extended for calculation of next to next to nearest neighbor correlation functions as well as for calculation of correlation functions in XXZ model.

cond-mat.str-el↗
arXiv2003

Thermodynamic Bethe Ansatz for the Spin-1/2 Staggered XXZ- Model

We develop the technique of Thermodynamic Bethe Ansatz to investigate the ground state and the spectrum in the thermodynamic limit of the staggered $XXZ$ models proposed recently as an example of integrable ladder model. This model appeared due to staggered inhomogeneity of the anisotropy parameter $Δ$ and the staggered shift of the spectral parameter. We give the structure of ground states and lowest lying excitations in two different phases which occur at zero temperature.

hep-th↗