Reply to Correspondence on "Suppressing Energy Migration via Antiparallel Spin Alignment in One-Dimensional Mn²⁺...

To address concerns regarding the photoluminescence quantum yield (PLQY) or radiative rate (k_r) of Cd²⁺ doped (CH₃)₄NMnCl₃ (TMMC:0.2Cd²⁺), we conducted additional experiments on Cu impurity content, PLQY, and magneto-optical spectra of both TMMC and TMMC:0.2Cd²⁺. Our results show that TMMC consistently exhibits a higher PLQY than TMMC:0.2Cd²⁺, even though TMMC contains trace Cu impurities, which typically act as luminescence-quenching centers. The PLQY and k_r values for TMMC:0.2Cd²⁺ in our previous study may have been underestimated due to the susceptibility of halide samples and PLQY measurements to experimental conditions and the absence of a standardized measurement method. However, the predicted radiative rate (k_r = 1.12 × 10³ s^-1) for TMMC:0.2Cd²⁺, as derived from the pressure-dependent model in the Correspondence, leads to an unphysical negative nonradiative rate (k_nr) when considering the experimentally observed decay lifetime of 0.935 ms. This inconsistency renders the predicted data unconvincing, despite the theoretical validity of the model. Furthermore, the field-dependent PL intensities and decay lifetimes of TMMC and TMMC:0.2Cd²⁺ confirm that the antiparallel spin ordering of Mn²⁺ ions plays a role similar to Cd²⁺ in suppressing excitonic energy migration toward Cu²⁺ trapping centers.