Quantum Correlation Based on Uhlmann Fidelity for Gaussian States

A quantum correlation [Formula: see text] for [Formula: see text]-mode continuous-variable systems is introduced in terms of local Gaussian unitary operations performed on Subsystem A based on Uhlmann fidelity F. This quantity is a remedy for the local ancilla problem associated with the geometric measurement-induced correlations; is local Gaussian unitary invariant; is non-increasing under any Gaussian quantum channel performed on Subsystem B;and is an entanglement monotone when restricted to pure Gaussian states in the [Formula: see text]-mode case. A concrete formula for [Formula: see text]-mode symmetric squeezed thermal states (SSTSs) is presented. We also compare [Formula: see text] with other quantum correlations in scale, such as Gaussian quantum discord and Gaussian geometric discord, for two-mode SSTSs, which reveals that [Formula: see text] has some advantage in detecting quantum correlations of Gaussian states.