H. Y. Yuan

Two pendulums linked by a spring of light begin to swing in unison without ever touching. In the quantum world, such synchronization means something more: particles lose their individuality and become a single object.

In most magnetic materials, a domain wall, the boundary between regions with different magnetization, moves in one direction under current, set by the current's direction. But in ferrimagnets near a special point where the angular momenta of two sublattices cancel each other, the behavior changes.