Magnetic Flux Tuning of Spin Chirality in Mott Insulators with Ring Exchanges

A manifestation of the many-body Aharonov-Bohm effect in the magnetic-flux-tuned Mott insulators with three-spin and four-spin ring exchanges, presents as an effective tool to manipulate the ground-state spin chirality, such as, tune the magnitude continuously, switch an abrupt jump, or even reverse its sign. Such a mechanism is demonstrated explicitly in both quasi-one-dimensional ladders and two-dimensional lattices with triangles as elementary plaquettes.