Yuan Shuai, Chen Weijin, Liu Jianyi, Liu Yulan, Wang Biao, Zheng Yue
School of Engineering, Sun Yat-sen University, Guangzhou 510275, People's Republic of China. State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-sen University, Guangzhou 510275, People's Republic of China. Micro & Nano Physics and Mechanics Research Laboratory, School of Physics, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
J Phys Condens Matter. 2018 Nov 21;30(46):465304. doi: 10.1088/1361-648X/aae5e9. Epub 2018 Oct 3.
The controllability of vortex state in ferroelectric nanodisks under the effect of external torsion is investigated in this work based on phase-field simulation. We discover a novel Bloch skyrmion-like state in ferroelectric nanodisks due to the combining effect of the torsion and the depolarization field. Moreover, a new strategy is proposed to achieve deterministic switching of the vortex chirality in the ferroelectric nanodisks. On the one hand, if a fixed external electric field is applied to the nanodisk, the vortex chirality can be switched by the torsion force. On the other hand, if we apply a fixed torsion force to the nanodisk, the vortex chirality can be readily switched by an external electric field. The feasibility of both mechanical and electrical switching of the vortex in the ferroelectric nanodisks is based on the trilinear coupling between the toroidization, polarization and shear strain of the system. The influences of temperature, electric field, torsion, and size of the nanodisk on the control of the vortex state are further revealed. Our findings shed light on the practical control and application of ferroelectric dipole vortices.
基于相场模拟，本文研究了外部扭转作用下铁电纳米盘涡旋态的可控性。由于扭转和退极化场的共同作用，我们在铁电纳米盘中发现了一种新型的类布洛赫斯格明子态。此外，还提出了一种新策略来实现铁电纳米盘中涡旋手性的确定性切换。一方面，如果对纳米盘施加固定的外部电场，涡旋手性可以通过扭转力来切换。另一方面，如果对纳米盘施加固定的扭转力，涡旋手性可以很容易地通过外部电场来切换。铁电纳米盘中涡旋的机械和电切换的可行性基于系统的环带化、极化和剪切应变之间的三线性耦合。进一步揭示了温度、电场、扭转和纳米盘尺寸对涡旋态控制的影响。我们的研究结果为铁电偶极涡旋的实际控制和应用提供了启示。
