Enhancement of the Magnetoelectric Effect Using the Dynamic Jahn-Teller Effect in a Transition-Metal Complex

• Published in: Physical review letters Vol. 128; no. 11; p. 117601
• Main Authors: Otsuki, Yasunao, Kimura, Shojiro, Awaji, Satoshi, Nakano, Motohiro
• Format: Journal Article
• Language: English
• Published: United States 18.03.2022
• ISSN: 1079-7114
• DOI: 10.1103/physrevlett.128.117601

In this Letter, a novel mechanism to enhance the magnetoelectric (ME) coupling between electric polarization and magnetism using the dynamic Jahn-Teller (JT) effect is demonstrated. Electric polarization of over 100  μC/m^{2} is induced by the magnetic field owing to the second-order ME effect in the noncentrosymmetric transition metal complex [Mn^{III}(taa)]. This appearance of electric polarization does not require magnetic order in contrast to the linear ME effect in ME multiferroic materials. The value of the electric polarization is 1 order larger than that induced by the second-order ME effect, which originates from the p-d hybridization. Our calculation, taking into account the single-ion-type magnetic anisotropy originating from the spin-orbit interaction and ferrodistortive intermolecular interaction, verifies that the alignment of the JT distortion by the magnetic field results in the large electric polarization observed. Thus, our results provide a new method to gain strong ME coupling by tuning the atomic displacement using a magnetic field.