We study entanglement and squeezing of a cluster of spin systems under the influence of the two-axis countertwisting Hamiltonian. The squeezing parameters given by Wineland et al and also by Kitagawa et al. are chosen as the criteria of spin squeezing. The criterion of pairwise entanglement is chosen to be the concurrence and that of the bipartite entanglement the linear entropy. We also define...

in this paper, we study the electronic properties of a concentric triple quantum ring using exact diagonalization technique. the energy spectra and magnetization for a single electron and two electrons, in the presence of an applied magnetic field, are calculated and discussed. it is shown that, for two-interacting electrons, the period of aharonov-bohm oscillations decreases to the half of tha...

the coherent anomaly method and a cluster mean-field approach combined with finite-sizescaling extrapolation were used to determine the critical temperature and the critical exponents of as =1 ising chain with a long-range interaction in the form of 1/ r1+σ . the results of criticaltemperature are in good agreement with the recent results of the finite-range scaling method and aremore accurate ...

In recent work,N = 2 supersymmetry has been proposed as a tool for the analysis of itinerant, correlated fermions on a lattice. In this paper we extend these considerations to the case of lattice fermions with spin 1/2 . We introduce a model for correlated spin-1/2 fermions with a manifest N = 4 supersymmetry, and analyze its properties. The supersymmetric ground states that we find represent h...

An action with unconventional supersymmetry was introduced in an earlier paper. Here it is shown that this action leads to standard physics for fermions and gauge bosons at low energy, but to testable extensions of standard physics for fermions at high energy and for fundamental bosons which have not yet been observed. For example, the Lorentz-violating equation of motion for these bosons impli...