Crystalline nanostrings have the potential to outperform SiN strings, provided they exhibit a comparable tensile stress. One possible material system to realize crystalline, yet pre-stressed strings are InGaP heterostructures. We demonstrate high Q InGaP string resonators, and characterize their anisotropic elastic properties arising from the crystalline structure of the underlying InGaP crystal.

See: M. Bückle et al., Appl. Phys. Lett. 113, 201903 (2018)