In terms of spin coherent states we have investigated topological defects in 2D S = 1 (pseudo)spin quantum system with the bilinear and biquadratic isotropic exchange in the continuum limit. The proper Hamiltonian of the model can be written as bilinear on the generators of SU(3) group (Gell-Mann matrices). Knowledge of such group structure enables us to obtain some new exact analytical results...

Elemental monolayers of the group 14 with a buckled honeycomb structure, namely silicene, germanene, stanene, and plumbene, are known to demonstrate spin splitting as result an electric field parallel their high symmetry axis which is capable tuning topological phase between quantum Hall insulator ordinary band insulator. We perform first-principles calculations based on density functional theo...

Abstract. In 1989, Vaughan Jones introduced spin models and showed that they could be used to form link invariants in two different ways—by constructing representations of the braid group, or by constructing partition functions. These spin models were subsequently generalized to so-called 4-weight spin models by Bannai and Bannai; these could be used to construct partition functions, but did no...

The spin degrees of freedom for the relativistic particle are described by either Lorentz group variables (classically) or Grassmann variables (pseudo-classically). The relationship between those two descriptions are given. In doing that, appropriate constraints are constructed to put into the lagrangian. Especially a natural relation of Lorentz group variables and Grassmann variables is obtain...

Funding information UK-EPSRC Grant ‘Attosecond Electron Dynamics in Molecular and Condensed Phase Systems’, Grant/Award Number: EP/I032517/1 Abstract We present an implementation of the spin-dependent unitary group approach to calculate spin densities for configuration interaction calculations in a basis of spin symmetry-adapted functions. Using S eigenfunctions helps to reduce the size of conf...

For certain nonmagnetic solids with low symmetry the occurrence of spin-polarized longitudinal currents is predicted. These arise due to an interplay of spin-orbit interaction and the particular crystal symmetry. This result is derived using a group-theoretical scheme that allows investigating the symmetry properties of any linear response tensor relevant to the field of spintronics. For the sp...

in this paper we studied the thermal negativity in a two-qubit xx spin ½ chain model and xxx spin1/2 chain model(isotropic heisenberg model)spin-1/2 chain subjected to an external magnetic field inz direction. we calculate analytical relation for the thermal negativity for two qubit xx and xxx spinchain models in the external magnetic field. effects of the magnetic field and temperature on then...