Abstract:Give two quantum channels acting on di?erent systems, we provide a natural and powerful method for coupling them by virtue of correlations between local environments. As an application, we demonstrate, through very simple examples, that separable (unentangled) correlations are a useful resource for preserving entanglement, which otherwise would be completely destroyed by entanglement breaking channels if environmental correlations were absent. This reveals a mechanism for engineering environments in ˉghting decoherence.