Brightened Optical Transition as Indicator of Multiferroicity in a Layered Antiferromagnet
Materials known as multiferroics exhibit more than one primary ferroic order in a given phase. The coexistence of multiple physical phases is highly interesting as by coupling these orders, we can deterministically control and understand the origins of states of matter. CrPS4, a two-dimensional layered antiferromagnetic semiconductor, has already attracted interest because of its exceptional tunability through external electric fields, offering an unprecedented platform to tailor interactions between spin and charge degree of freedom.
As CrPS4 enters the antiferromagnetic state, the researchers observed a new luminescent transition with peculiar energetic and polarization characteristics. This discovery shed light on the fluorescence pathway of photoexcited carriers and revealed that this brightened transition correlates with an enhanced non-linear optical response in the material. These findings can be attributed to a transition from an anti-ferro to a ferro distortive arrangement around chromium ions inducing a strong in-plane electrical polarization when the material enters the magnetic state.
These results underscore the tight link between lattice dynamics and electronic transition in magnetic van der Waals materials. Furthermore, they raise intriguing questions about the driving forces behind ferroic states and whether these states can be switched using external fields. The coupling of these ferroic orders heralds the potential to unlock innovative device functionalities.
Contact
Jérémie Teyssier
Department of Quantum Matter Physics
+41 22 379 35 16
Jeremie.Teyssier@unige.ch
Based on an article published recently in
Advanced Science