Dispersion of Electric-Field-Induced Faraday Effect in MagnetoelectricCr2O3

In an antiferromagnet, spins arrange in opposing sublattices with mutually compensating magnetization, and in real systems there can be different domains. Identifying a specific antiferromagnetic domain is notoriously difficult, but the authors' tabletop setup allows just that, for magnetoelectric antiferromagnets such as chromia, which rotate the polarization of transmitted light in response to an electric field. In chromia, domain states can be not just $d\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}d$, but also $s\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}d$---a key property for ultralow-power spintronic memory and logic devices.