Experimental Characterization of Quantumness Using the Uncertainty Principle, Coherence, and Nonlocality.

Heisenberg's uncertainty principle, coherence, and Bell nonlocality have been individually examined through many experiments. In this Letter, we systematically characterize all of this quantumness in a unified manner. We first construct universal uncertainty relations to reveal intrinsic features of incompatible measurements, which include all the state-independent uncertainties as special cases. We further extend to witness both quantum coherence and Bell nonlocality. We finally perform experiments with unified two-photon states and validate the uncertainty principle, coherence, and Bell nonlocality within experimental error. Our methods for witnessing quantumness are valuable in characterizing quantum correlations in quantum information processing.