Nonclassical correlations represent fundamental physical resources that play a crucial role in quantum information processing. In this work, we introduce a generalized nonclassicality quantifier based on metric-adjusted skew information, which aims to characterize the intrinsic nonclassical features of bosonic field states. The proposed nonclassicality quantifier is formally defined as the maximum metric-adjusted skew information between a quantum state and the homodyne rotated quadrature operator, which can effectively reflect the phase-dependent characteristics of the light field and is therefore suitable for capturing nonclassical effects. Notably, our findings reveal that coherent states exhibit a distinct threshold behavior, enabling a precise distinction between classical and nonclassical regimes. Furthermore, through rigorous analysis and comparative evaluation across a set of representative quantum states, we demonstrate that the quantifier not only captures essential nonclassical merits, but also detects entanglement by identifying violations of the additivity property that holds for separable states. As a result, this framework establishes a unified and mathematically rigorous approach for quantifying nonclassicality in both separable and entangled systems, thereby contributing valuable insights to the advancement of quantum resource theories.

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• Quantum correlations, foundations & formalism
• Quantum information theory