Non-simple flow behavior in a polar van der Waals liquid: structural relaxation under scope

The non-exponential character of the structural relaxation is considered one of the hallmarks of the glassy dynamics and in this context, the singular shape observed by dielectric techniques has attracted the attention of the community for long time. Particularly, the exceptionally narrow dielectric response of polar glass formers has been attributed so far to dipolar cross correlations. Here we show that dipole interactions can couple to shear stress and modify the flow behavior preventing the occurrence of the simple liquid behavior. We discuss our findings in the general framework of the glassy dynamics and the role of intermolecular interactions.