A meso--scale model, shear transformation zone dynamics (STZ dynamics), is employed to investigate the connections between structure and deformation of metallic glasses. The present STZ dynamics model is adapted to incorporate a structure--related state variable, and evolves via two competing processes: STZ activation that creates free volume vs. diffusive rearrangement that annihilates it. The dynamical competition between these two processes gives rise to an equilibrium excess free volume that can be connected to flow viscosity via the phenomenological Vogel--Fulcher--Tammann relation in relaxed structures near the glass transformation temperature. On the other hand, the excess free volume allows glasses to deform at low temperatures via shear localization into shear bands, even in presence of internal stress distributions that arise upon cooling after processing.

A scalable approach for integrated photonic networks in single-crystal diamond using triangular etching of bulk samples is presented. We describe designs of high quality factor (Q=2.51×10 6 ) photonic crystal cavities with low mode volume, which are connected via waveguides supported by suspension structures with predicted transmission loss of only 0.05 dB. We demonstrate the fabrication of these structures using transferred single-crystal silicon hard masks and angular dry etching, yielding photonic crystal cavities in the visible spectrum with measured quality factors in excess of Q=3×10 3 .

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