We study Wigner function of a system describing entanglement of two cat-states. Quantum interferece arising due to entanglement is shown to produce sub-Planck structures in the phase-space plots of the Wigner function. Origin of these structures in our case depends on entanglement unlike those in Zurek \cite{Zurek}. It is argued that the entangled cat-states are better suited for carrying out precision measurements.
@article{arxiv.0704.2677,
title = {Entanglement induced Sub-Planck structures},
author = {Jitesh R. Bhatt and Prasanta K. Panigrahi and Manan Vyas},
journal= {arXiv preprint arXiv:0704.2677},
year = {2009}
}