Credit: Image courtesy of Yong-Lei Wang, Zhi-Li Xiao, and Wai-Kwong Kwok, Argonne National Laboratory, University of Notre Dame, and Northern Illinois University.
Nanomagnetic attraction. In a magnetic charge ice with nanoscale magnets arranged in a two-dimensional lattice, each nanomagnet produces a pair of magnetic charges, one positive (red ball on the north pole) and one negative (blue ball on the south pole). The magnetic flux lines (white) point from positive charges to negative charges. Research allowed construction of arrays of reconfigurable nanomagnets (insert). Manipulating the nanomagnets produces three distinct types of states that are reconfigurable (insert).