Nonlinear Dynamics of Coherent Parametric Amplification in Multipartite two-level System under Intrinsic Decoherence

arXiv:2606.25860v1 Announce Type: new Abstract: In this work, we study the dynamics of global quantum discord and quantum Fisher information in a multipartite system of two-level atoms interacting with a coherent field. The model includes parametric amplification, Kerr-type nonlinearity, and intrinsic decoherence to examine how these effects control quantum correlations and parameter-estimation sensitivity. The results show that, without intrinsic decoherence, both quantities exhibit rapid oscillations with clear collapse and revival behavior. Strong Kerr nonlinearity and strong parametric amplification enhance global quantum discord, while quantum Fisher information becomes maximum under a suitable balance of Kerr nonlinearity and amplification strength. Increasing the number of atoms generally strengthens global quantum discord but does not always improve quantum Fisher information. Intrinsic decoherence damps the oscillations and drives the system toward steady-state behavior.