In this chapter, we discuss the spin moiré engineering in three dimensions. First, we present the results of controlling spin moirés with the amplitudes of superposed waves through spatial anisotropy. We clarify that spatial anisotropy can drive the modulation of the amplitudes of constituent waves in anisotropic ways that lead to the topological phase transition accompanied by the creation and annihilation of hedgehogs and antihedgehogs for 3Q- and 4Q-hedgehog lattices (HLs). Next, we investigate the effect from the twist angle of superposed waves. Focusing on the 3Q-HL, we find that the variation of the relative angles between the constituent three helices leads to the topological transitions with successive changes in the number of hedgehogs and antihedgehogs. Next, we systematically clarify the effect of the phase shift in the 4Q-HLs. By using the hyperspace representation, we find that the total number of hedgehogs and antihedgehogs unprecedentedly ranges up to 48. Furthermore, we also clarify that applying the magnetic field drives the phase shift accompanied by the topological phase transition with pair annihilation of hedgehogs and antihedgehogs. Finally, we investigate the control of the drift motions of the 3Q-HL caused by an electric current. We discover that the hedgehogs exhibit the peculiar current-induced motion including two extremes: purely longitudinal motion without any transverse one and purely transverse motion without any longitudinal one. Notably, we clarify that these dynamics can be switched by changing the direction and amplitudes of the external magnetic field and electric current.

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Spin Moiré Engineering in Three Dimensions

  • Kotaro Shimizu

摘要

In this chapter, we discuss the spin moiré engineering in three dimensions. First, we present the results of controlling spin moirés with the amplitudes of superposed waves through spatial anisotropy. We clarify that spatial anisotropy can drive the modulation of the amplitudes of constituent waves in anisotropic ways that lead to the topological phase transition accompanied by the creation and annihilation of hedgehogs and antihedgehogs for 3Q- and 4Q-hedgehog lattices (HLs). Next, we investigate the effect from the twist angle of superposed waves. Focusing on the 3Q-HL, we find that the variation of the relative angles between the constituent three helices leads to the topological transitions with successive changes in the number of hedgehogs and antihedgehogs. Next, we systematically clarify the effect of the phase shift in the 4Q-HLs. By using the hyperspace representation, we find that the total number of hedgehogs and antihedgehogs unprecedentedly ranges up to 48. Furthermore, we also clarify that applying the magnetic field drives the phase shift accompanied by the topological phase transition with pair annihilation of hedgehogs and antihedgehogs. Finally, we investigate the control of the drift motions of the 3Q-HL caused by an electric current. We discover that the hedgehogs exhibit the peculiar current-induced motion including two extremes: purely longitudinal motion without any transverse one and purely transverse motion without any longitudinal one. Notably, we clarify that these dynamics can be switched by changing the direction and amplitudes of the external magnetic field and electric current.