Performance of Quantum Correlations and Estimation of Gravitational State under a Joint Thermal-Bosonic Reservoir

Abstract

We address the dynamics of quantum correlations in a two-qubit gravitational cat state when initially prepared as thermal state. The initial thermal gravcat state is allowed to couple with a bosonic reservoir driven by Ohmic type noise. The resourcefulness of the gravcat system is then examined using various quantum correlation functions, namely, steerability, and Bell non-locality. In addition, the interplay of entropy is significant in open quantum systems, therefore, the entropy generation is discussed in relation to quantum correlations dynamics. We find that gravitational state resourceful but limited to certain conditions. For example for the increase in gravitational strength, quantum correlations decay rapidly, and entropy is generated in the system. Besides, increasing the excited-ground state separation enhances steerability but reduces Bell non-locality. The higher temperature limit is found weakening quantum correlations. Ohmic noise cut-off frequency also diminishes quantum correlations and support entropy generation in the gravcat state. In comparison, the Steerability is found more strengthen quantum correlations than Bell non-locality, while both these functions have opposite relation with entropy in the system. Finally, we also provide the detail estimation of the inclusive parameters using quantum Fisher information approach.