Instantaneous Normal Modes Reveal Structural Signatures for the Herschel-Bulkley Rheology in Sheared Glasses

The Herschel-Bulkley law, a universal constitutive relation, has been empirically known to be applicable vast range of soft materials, including sheared glasses. Although the Herschel- Bulkley law attracted public attention, its structural origin remained an open question. In this letter, by means atomistic simulation binary Lennard-Jones glasses, we report that instantaneous normal modes with negative eigenvalues, or so-called imaginary modes, serve as signatures for rheology in