  We report a systematic study of spin transport in antiferromagnetic (AF)
insulators having a wide range of ordering temperatures. Spin current is
dynamically injected from Y3Fe5O12 (YIG) into various AF insulators in
Pt/insulator/YIG trilayers. Robust, long-distance spin transport in the AF
insulators is observed, which shows strong correlation with the AF ordering
temperatures. We find a striking linear relationship between the spin decay
length in the AFs and the damping enhancement in YIG, suggesting the critical
role of magnetic correlations in the AF insulators as well as at the AF/YIG
interfaces for spin transport in magnetic insulators.
