论文标题
在氧化物界面设计浆果曲率的自旋和轨道来源
Designing spin and orbital sources of Berry curvature at oxide interfaces
论文作者
论文摘要
量子材料可以显示出植根于电子波形几何形状的物理现象。相应的几何张量的特征在于一个称为浆果曲率（BC）的新兴场。当具有不同自旋，轨道或sublattice量子数的电子状态在有限晶体动量时杂交时，通常会出现大BC。在迄今已知的所有材料中，BC都是由单一类型的量子数的杂交触发的。在这里，我们报告了具有旋转和轨道为BC的第一个材料系统的发现：laalo $ _3 $/srtio $ _3 $接口沿[111]方向生长。我们独立检测这两个来源，并通过测量异常的平面霍尔效应直接探测与自旋量子数相关的BC。观察非线性霍尔效应具有时间反向对称性信号，大轨道介导的BC偶极子。不同形式的BC共存实现了单个材料中自旋形式和光电功能的结合。
Quantum materials can display physical phenomena rooted in the geometry of electronic wavefunctions. The corresponding geometric tensor is characterized by an emergent field known as Berry curvature (BC). Large BCs typically arise when electronic states with different spin, orbital or sublattice quantum numbers hybridize at finite crystal momentum. In all materials known to date, the BC is triggered by the hybridization of a single type of quantum number. Here, we report the discovery of the first material system having both spin and orbital-sourced BC: LaAlO$_3$/SrTiO$_3$ interfaces grown along the [111] direction. We detect independently these two sources and directly probe the BC associated to the spin quantum number through measurements of an anomalous planar Hall effect. The observation of a nonlinear Hall effect with time-reversal symmetry signals large orbital-mediated BC dipoles. The coexistence of different forms of BC enables the combination of spintronic and optoelectronic functionalities in a single material.
