A research team has successfully observed a novel nonreciprocal optical phenomenon, termed "electric field-induced nonreciprocal directional dichroism", in antiferromagnets with breaking time-reversal symmetry.
Antiferromagnets, characterized by magnetic moments arranged such that their net sum is zero, have been increasingly recognized for their diverse phenomena and functionalities, which vary depending on the specific arrangement of their magnetic moments. Recently, antiferromagnets that break the system's time-reversal symmetry have gained significant attention.
In this study, the team achieved the first observation of electric field-induced nonreciprocal directional dichroism in a time-reveral-symmetry-broken antiferromagnet Co₂SiO₄, which is characterized by a magnetic toroidal monopole. This phenomenon was observed as a change in light absorption induced by an applied electric field. Furthermore, by mapping the two-dimensional spatial distribution of this phenomenon, the team demonstrated the visualization of the magnetic domain structures.
These findings not only advance our understanding of the unique optical properties of antiferromagnets but also hold promise for the development of novel devices utilizing antiferromagnets in fields such as spintronics.
Papers
Journal: Advanced Materials
Title: Electric Field-Induced Nonreciprocal Directional Dichroism in a Time-Reversal-Odd Antiferromagnet
Authors: Takeshi Hayashida*, Koei Matsumoto, Tsuyoshi Kimura*
Ferroelectricity Induced by a Combination of Crystallographic Chirality and Axial Vector
Imaging and control of magnetic domains in a quasi-one-dimensional quantum antiferromagnet BaCu2Si2O7
