Artificial spin-ice systems have been used to date as microscopic models of frustration induced by lattice topology, as they allow for the direct visualization of spin arrangements and textures. However, the engineering of frustrated ice states in which individual spins can be manipulated in situ and the real-time observation of their collective dynamics remain both challenging tasks. Recently, an analogue system has been proposed theoretically, where an optical landscape confined colloidal particles that interacted electrostatically. Here we realize experimentally another version of a colloidal artificial ice system using interacting magnetically polarizable particles confined to lattices of bistable gravitational traps. We show quantitatively that ice-selection rules emerge in this frustrated soft matter system by tuning the strength of the pair-interactions between the microscopic units. By using optical tweezers, we can control particle positioning and dipolar coupling, we introduce monopole-like defects and strings and use loops with defined chirality as an elementary unit to store binary information.

Date Published: 10 November 2016
PDF: 1 pages
Proc. SPIE 9922, Optical Trapping and Optical Micromanipulation XIII, 992205 (10 November 2016); doi: 10.1117/12.2236647

Published in SPIE Proceedings Vol. 9922:
Optical Trapping and Optical Micromanipulation XIII
Kishan Dholakia; Gabriel C. Spalding, Editor(s)