Quantum-correlation of neutral charmed mesons at BESIII

BESIII has recently collected a large data sample at the ψ(3770) energy point, with an integrated luminosity of 20 fb⁻¹. The neutral D⁰D̄⁰ pairs produced at ψ(3770) are in a C-odd correlated state, offering a unique laboratory for measuring the strong-phase differences between D⁰ and D̄⁰ decays. These parameters are crucial inputs for $C\!P$-violation studies in heavy-flavor physics, such as determining the CKM angle γ and charm-mixing parameters, searching for indirect $C\!P$ violtion in the charm sector. In this presentation, we report recent progresses on new or improved measurements of the strong-phase differences in various neutral D decays at BESIII. We also present results on the $C\!P$-even fractions for multi-body decays. Finally, we discuss measurements of strong phase difference from additional D⁰D̄⁰ pairs produced at 4180 MeV.