Imaging and control of magnetic domains in a quasi-one-dimensional quantum antiferromagnet BaCu2Si2O7

Authors

Masato Moromizato, Takeshi Miyake, Takatsugu Masuda, Tsuyoshi Kimura, and Kenta Kimura

Abstract

We visualize antiferromagnetic domains in a representative quasi-one-dimensional 𝑆=1/2 quantum antiferromagnet, BaCu₂Si₂O₇, using nonreciprocal directional dichroism, which differentiates the optical absorption of a pair of antiferromagnetic domains. Opposite antiferromagnetic domains, each about submillimeter in size, are found to coexist in a single-crystal specimen, and the domain walls run predominantly along the spin chains. We also demonstrate that the domain walls can be moved by an applied electric field through a magnetoelectric coupling and that the direction of the domain walls is maintained during the motion. We explain the domain wall anisotropy by the quasi-one-dimensional nature of the exchange interactions. This Letter will contribute to the understanding of the domain physics of quasi-one-dimensional quantum antiferromagnets.

Physical Review Letters: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.133.086701