“More is different”: Nanofabricated chiro-optical material based on 8-fold intergrowth of gyroid
In a totally different context to the original quote and article, Phil Anderson’s quote “More is different” holds also for the chiro-optical response of gyroid-based photonic materials. Eight intergrown Gyroids give a substantially different chiro-optical response than the single gyroid. The group theoretic prediction from Matthias Saba’s PhD work (Saba et al, PRB 2013) has now been experimentally validated by Nanofabrication experiments in the Center for Microphotonics at Swinburne University (Turella et al, Optics Letters, 2015).
The single gyroid (also known as 1-srs) shows circular dichroism, i.e. a difference in transmission amplitude of left- and right-circularly-polarised light (Mater Today Proc 2014). It turns out that 8 equal-handed gyroid nets can be intergrown in a highly symmetric fashion without overlap between the individual networks, leading to a structure called 8-srs (Hyde et al, EPL 2000, EPJB 2000; Evans et al 2013). This structure, an eight-fold copy of the single gyroid, shows no circular dichroism in transmission, but very strong optical activity (rotation of the optical polarization plane) even when realised as a lossless polymeric photonic crystal. A truly different photonic response compared to the 1-srs case!
References:
- P. Anderson, Science 4, 4047, 1972.
- Turella et al, Optics Letters 40, 4795-4798 (2015)
- Saba et al, Phys Rev B 88, 245116 (2013)
- M. Saba, B. Wilts, et al., Materials Today Proceeding Volume 1, Supplement, 2014, Pages 193–208
- S. T. Hyde and S. Ramsden, Europhys. Lett. 50, 135 (2000).
- S. T. Hyde and C. Oguey, Eur. Phys. J. B 16, 613 (2000).
- M. E. Evans, V. Robins, and S. T. Hyde, Acta Crystallogr., Sect. A 69, 241 (2013).