Thermodynamic Cost of Creating Global Quantum Discord and Local Quantum Uncertainty

Abstract

In this paper, we investigate the fundamental limitations arising from initial temperature of two initially uncorrelated thermal quantum systems for creating quantum correlations. In order to establish the quantum correlations between the systems, we allow ourselves to perform a global unitary operation which maximizes entanglement between them as given in Verstraete et al. (Phys. Rev. A 64, 012316 2001). We demonstrate the energy cost of the created correlations between the uncorrelated thermal quantum systems via performing such a global unitary operation. Also, we derive an analytical expression for global quantum discord (GQD) and local quantum uncertainty (LQU) as measures of quantum correlations and by comparing them with the existing optimal entanglement, we observe that the GQD and the LQU only decay asymptotically in contrast to the entanglement which is vanishes completely at a finite critical temperature.