Physics

Prof. S. Lakshmi Bala
IIT Madras

ABSTRACT: We examine nonclassical effects such as the extent of 
squeezing and entanglement in dissipationless models of bipartite and 
tripartite interactions with inherent nonlinearities. These include the case of a multilevel atom interacting with a radiation field  and a three-level atom interacting with two radiation fields.

We demonstrate the procedure to quantify the extent of both quadrature and entropic squeezing directly from tomograms, thus circumventing detailed state reconstruction. The entanglement dynamics shows a high degree of sensitivity to intensity-dependence in couplings between subsystems, leading to a bifurcation cascade.

  In the case of the bipartite system,  we have identified two 
entanglement indicators from relevant tomograms which agree in gross 
qualitative predictions of the extent of entanglement with those of 
standard measures such as the subsystem von Neumann entropy (SVNE). We have attempted to analyse the origin of the discrepancies between the predictions of these indicators and SVNE.