Rikken Geert L J A, Avarvari Narcis
Laboratoire National des Champs Magnétiques Intenses UPR3228 CNRS/EMFL/INSA/UGA/UPS, Toulouse & Grenoble, France.
Univ Angers, CNRS, MOLTECH-Anjou, SFR MATRIX, F-49000, Angers, France.
Nat Commun. 2022 Jun 22;13(1):3564. doi: 10.1038/s41467-022-31225-3.
The combination of chirality and magnetism has steadily grown over the last decennia into an area of intense research. Magnetochiral anisotropy, chirality-induced spin-selectivity and helimagnetism are the most prominent phenomena resulting from this combination, touching different systems like topological (semi-)metals and insulators, quantum magnets, type II multiferroics and enantio-selective synthesis. As an extension to this area, we argue, based on symmetry arguments, that magnetochiral anisotropy will manifest itself in the displacement current in chiral dielectrics in a magnetic field. We confirm this conjecture by the experimental observation of very strong dielectric magnetochiral anisotropy near the ferroelectric phase transitions of triglycine sulfate and Rochelle salt, two of the oldest and most investigated chiral ferroelectrics. This effect opens a new playground in the study and characterisation of all chiral dielectrics. With our discovery, magnetochiral anisotropy now covers the (di)electrical properties of all condensed matter, from insulators to superconductors.
在手性与磁性相结合的领域，过去十年间，该领域的研究热度稳步攀升。磁手性各向异性、手性诱导自旋选择性和螺旋磁性是这种结合产生的最显著现象，涉及不同的体系，如拓扑（半）金属和绝缘体、量子磁体、II型多铁性材料和对映体选择性合成。作为该领域的拓展，基于对称性论证，我们认为磁手性各向异性将在磁场中的手性电介质的位移电流中表现出来。我们通过实验观察到，在硫酸三甘肽和酒石酸钾钠这两种历史最悠久、研究最多的手性铁电体的铁电相变附近，存在非常强的介电磁手性各向异性，从而证实了这一推测。这种效应为所有手性电介质的研究和表征开辟了一个新的领域。随着我们的发现，磁手性各向异性现在涵盖了从绝缘体到超导体的所有凝聚态物质的（介）电性质。
