The ferromagnetic condensate is a well known device for mass generation in particle physics ever since the seminal work of Nambu and Jona-Lasinio. This condensate is a coherent state of particles with vanishing momentum. We suggest in this talk the use of another type of condensate in Quantum Field Theory which is a coherent state consisting of particles with non-zero momentum. The field operat...

In this paper, using high order perturbative series expansion method, the critical exponents of the order parameter and susceptibility in transition from ferromagnetic to disordered phases for 1D quantum Ising model in transverse field, with ferromagnetic nearest neighbor and anti-ferromagnetic next to nearest neighbor interactions, are calculated. It is found that for small value of the frustr...

the effect of impurities on quantum chemical parameters of single-walled nanotubes (swnts) was studied using density functional theory (dft). the density of states (dos), fermi energy and thermodynamic energies of (5,5) carbon nanotubes were calculated in the presence of nitrogen impurity. it was found that this nanotube remains metallic after being doped with one nitrogen atom. the partial den...

The Monte Carlo analysis for the magnetic response of a single-walled nanotube using Metropolis and Wang-Landau algorithms is reported in present paper. architecture used study utilizes spin half Ising model with nearest neighbors interaction obtained various orderings, namely ferromagnetic, G-type anti-ferromagnetic, A-type C-type anti-ferromagnetic. It also found that phase changes from ferro...

We study the quantum 2D anti-ferromagnetic Ising model with Dzyaloshinskii-Moriya (DM) interaction using position space renormalization group (PSRG). In particular, we find that there exist a quantum phase transition between the anti-ferromagnetic phase and the chiral phase, which is the phase dominated by large DM interaction, at a finite value of the DM coupling in both one and two dimensions.

We apply the homotopy group theory in classifying the topological defects in atomic spin-1 and spin-2 Bose-Einstein condensates. The nature of the defects depends crucially on the spin-spin interaction between the atoms. We find the topologically stable defects both for spin-1 ferromagnetic and anti-ferromagnetic states, and for spin-2 ferromagnetic and cyclic states. With this rigorous approac...

We study XXX Heisenberg spin 1/2 anti-ferromagnet. We evaluate a probability of formation of a ferromagnetic string in the anti-ferromagnetic ground state in thermodynamics limit. We prove that for short strings the probability can be expressed in terms of Riemann zeta function with odd arguments.

We study XXX Heisenberg spin 1/2 anti-ferromagnet. We evaluate a probability of formation of a ferromagnetic string in the anti-ferromagnetic ground state in thermodynamics limit. We prove that for short strings the probability can be expressed in terms of Riemann zeta function with odd arguments.

We study XXX Heisenberg spin 1/2 anti-ferromagnet. We evaluate a probability of formation of a ferromagnetic string in the anti-ferromagnetic ground state in thermodynamics limit. We prove that for short strings the probability can be expressed in terms of Riemann zeta function with odd arguments.