Rewritable artificial magnetic charge ice

Rewritable artificial magnetic charge ice.

Yong-Lei Wang, Zhi-Li Xiao,Alexey Snezhko, Jing Xu,Leonidas E. Ocola, Ralu Divan,John E. Pearson, George W. Crabtree, Wai-Kwong Kwok

Science 352, 962 (2016)

Rewritable magnetic charge ices. (A) Sketch of the experimental setup: an MFM equipped with a 2D vector magnet. The 2D solenoid magnet provides magnetic fields in any desired orientation in the sample plane. The vertically magnetized MFM probe generates a stray magnetic field (green arrows) with in-plane components at the tip. (B) Magnetization loop of a single magnetic island, with an illustration of the write, erase, and read functions. M_x, magnetization along the island. (C to G) Magnetic force microscopy images of the patterned magnetic charge ice at the same area of the sample. (C) The initial state is a type I₁ state. (D) A square area of a type III₃ state was written in the center of (C). (E) A smaller square region of type III₃ order was erased back to a type I₁ state from (D). (F) A round region of type II₂ order was written onto the freshly erased area from (E). (G) “ICE” letters of type III₄ states were scribed on a type I background state.