Japanese Journal of Applied Physics ( IF 1.5 ) Pub Date : 2021-05-07 , DOI: 10.35848/1347-4065/abf949 Maoyuan Zheng 1, 2 , Zhigang Yin 1, 3 , Yong Cheng 1, 3 , Jinliang Wu 1 , Xingwang Zhang 1, 3, 4 , Jing Qi 2
We report the existence of bulk persistent spin texture in P4mm tetragonal BiFeO3, a ferroelectric with ultrahigh spontaneous polarization. Our density functional theory calculations reveal that tetragonal BiFeO3 exhibits sufficiently strong spin–orbit coupling, yielding a sizable Rashba coefficient of 0.31eV . More importantly, it is demonstrated that the polarization-induced spin–orbit field is unidirectional on the Z–Γ–X plane which contains the polar axis. Consequently, there emerges a momentum-independent spin texture, allowing a long-lived persistent spin helix with a wavelength of 23nm in the real space.
中文翻译:
四方 BiFeO 3 中的持久自旋织构
我们报告了在P 4 mm四方 BiFeO 3 中存在大量持久自旋结构,这是一种具有超高自发极化的铁电体。我们的密度泛函理论计算表明,四方 BiFeO 3表现出足够强的自旋轨道耦合,产生 0.31eV 的相当大的 Rashba 系数。更重要的是,证明了极化诱导的自旋轨道场在包含极轴的Z- Γ- X平面上是单向的。因此,出现了与动量无关的自旋纹理,允许在真实空间中存在波长为 23nm 的长寿命持久自旋螺旋。