IITB-Monash Research Academy, IIT Bombay, Mumbai, 400076, India.
School of Chemistry, University of Melbourne, Melbourne, VIC, 3010, Australia.
Nat Commun. 2017 Oct 18;8(1):1023. doi: 10.1038/s41467-017-01102-5.
Toroidal quantum states are most promising for building quantum computing and information storage devices, as they are insensitive to homogeneous magnetic fields, but interact with charge and spin currents, allowing this moment to be manipulated purely by electrical means. Coupling molecular toroids into larger toroidal moments via ferrotoroidic interactions can be pivotal not only to enhance ground state toroidicity, but also to develop materials displaying ferrotoroidic ordered phases, which sustain linear magneto-electric coupling and multiferroic behavior. However, engineering ferrotoroidic coupling is known to be a challenging task. Here we have isolated a {CrDy} complex that exhibits the much sought-after ferrotoroidic ground state with an enhanced toroidal moment, solely arising from intramolecular dipolar interactions. Moreover, a theoretical analysis of the observed sub-Kelvin zero-field hysteretic spin dynamics of {CrDy} reveals the pivotal role played by ferrotoroidic states in slowing down the magnetic relaxation, in spite of large calculated single-ion quantum tunneling rates.
环形量子态最有希望用于构建量子计算和信息存储设备,因为它们对均匀磁场不敏感,但与电荷和自旋电流相互作用,允许仅通过电手段来操纵这个磁矩。通过铁环形相互作用将分子环形体耦合成更大的环形磁矩,不仅可以增强基态环形度,还可以开发显示铁环形有序相的材料,这些材料具有线性磁电耦合和多铁性行为。然而,众所周知,工程铁环形耦合是一项具有挑战性的任务。在这里,我们分离出一个{CrDy}配合物,它表现出人们所追求的铁环形基态,具有增强的环形磁矩,仅源于分子内偶极相互作用。此外,对观察到的{CrDy}在零场下亚开尔文的零场滞后自旋动力学的理论分析表明,尽管计算出的单离子量子隧穿率很大,但铁环形态在减缓磁弛豫方面起着关键作用。