Mechanical hole burning spectroscopy: A comparison of two scenarios

A mechanical hole-burning (MSHB) scheme was constructed to compare the analogous observations to those from dielectric non-resonant spectral hole burning (NSHB) for glass-forming liquids near their glass transitions. We used the framework of the BKZ and Bernstein-Shokooh nonlinear viscoelastic constitutive equations to examine the modified responses in a way that does not invoke an explicit heterogeneous or homogeneous nature for the relaxation response. From the BKZ model only partial hole-burning features are observed in the modified shear modulus. The Bernstein-Shokooh model used to calculate the modified compliance shows no evidence at all of a hole-burning event. These results suggest that in addition to showing potential as a probe of dynamic heterogeneity, MSHB may also a prove to be a sensitive test for the validity of nonlinear constitutive laws.