  Artificial ices enable the study of geometrical frustration by design and
through direct observation. However, it has proven difficult to achieve
tailored long-range ordering of their diverse configurations, limiting both
fundamental and applied research directions. We designed an artificial spin
structure that produces a magnetic charge ice with tunable long-range ordering
of eight different configurations. We also developed a technique to precisely
manipulate the local magnetic charge states and demonstrate write-read-erase
multifunctionality at room temperature. This globally reconfigurable and
locally writable magnetic charge ice could provide a setting for designing
magnetic monopole defects, tailoring magnonics, and controlling the properties
of other two-dimensional materials.
