arXiv subjects

M. C. Valsakumar

Publications and source records attributed to M. C. Valsakumar.

21 records · Page 2Linked to original sources

arXiv2001

Interlayer Exchange Coupling in M/N/M Multilayer

The interlayer exchange coupling (IEC) of two local moment ferromagnetic layers separated by a non-magnetic spacer layer (M/N/M multilayer) is studied using the modified RKKY method along with the s-f model. The IEC exhibits oscillatory behaviour with respect to the spacer layer thickness and it oscillates between ferro- and antiferromagnetic configurations. The conventional RKKY method is also used to obtain the IEC and the results are compared with those obtained from the modified RKKY method which incorporates the electron correlation effects. We find significant correlation effects on the IEC and in fact the correlations alter the nature and magnitude of the magnetic coupling.

cond-mat↗

arXiv2001

Persistence and Life Time Distribution in Coarsening Phenomen

We investigate the life time distribution in one and two dimensional coarsening processes modelled by Ising - Glauber dynamics at zero temperature. We find that the life time distribution obeys a scaling ansatz, asymptotically. An independent life time model where the life times are sampled from a distribution with power law tail is presented, which predicts analytically the qualitative features of the scaling function.

cond-mat.stat-mech↗

arXiv1998

Chaos, Order Statistics and Unstable Periodic Orbits

We present a new method for locating unstable periodic points of one dimensional chaotic maps. This method is based on order statistics. The densities of various maxima of the iterates are discontinuous exactly at unstable periodic points of the map. This is illustrated using logistic map where densities corresponding to a small number of iterates have been obtained in closed form. This technique can be applied to the class of continuous time systems where the successive maxima of the time series behave as if they were generated from a unimodal map. This is demonstrated using Lorenz model.

chao-dyn↗