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We propose a modified metric based on the Hilbert-Schmidt norm and adopt it to define a rescaled version of the geometric measure of quantum discord. Such a measure is found not to suffer from pathological dependence on state purity. Although the employed metric is still non-contractive under quantum operations, we show that the resulting indicator of quantum correlations is in agreement with other bona fide discord measures in a number of physical examples. We present a critical assessment of the requirements of reliability versus computability when approaching the task of quantifying, or measuring, general quantum correlations in a bipartite state. [ABSTRACT FROM AUTHOR]

We review a recently developed theoretical approach to the experimental detection and quantification of bipartite quantum correlations (QCs) between a qubit and a d-dimensional system. Specifically, introducing a properly designed measure Q, the presented scheme allows us to quantify general QCs for arbitrary states of 2⊗d systems without the need to fully reconstruct them by tomographic techniques. We take in exam the specifics of the required experimental architecture in nuclear magnetic resonance (NMR) and optical settings. Finally we extend this approach to models of open system dynamics and discuss possible advantages and limitations in such a context. [ABSTRACT FROM AUTHOR]