The low energy dynamics of the anti-ferromagnetic Heisenberg spin S chain in the semiclassical limit S → ∞ is known to map onto the O(3) nonlinear σ model with a θ term in 1+1 dimension. Guided by the underlying dual symmetry of the spin chain, as well as the recently established topological significance of “dangling edge spins,” we report an exact mapping onto the O(3) model that avoids the co...

Numerical modelling of coherent spin relaxation in nanomagnets, formed by magnetic molecules of high spins, is accomplished. Such a coherent spin dynamics can be realized in the presence of a resonant electric circuit coupled to the magnet. Computer simulations for a system of a large number of interacting spins is an efficient tool for studying the microscopic properties of such systems. Coher...

background: in algeria, the data on infertility and its various causes are rare. recently, the introduction of assisted reproduction has allowed expecting that 300000 couples, which represent 7% of couples of reproductive age, face difficulty conceiving a child. knowing that most idiopathic cases are likely to be due to chromosomal abnormalities, we aimed to investigate genetic defects by karyo...