Ma Da, Arora Arpit, Vignale Giovanni, Song Justin C W
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371.
The Institute for Functional Intelligent Materials (I-FIM), National University of Singapore, 4 Science Drive 2, Singapore 117544.
Phys Rev Lett. 2023 Aug 18;131(7):076601. doi: 10.1103/PhysRevLett.131.076601.
Berry curvature and skew scattering play central roles in determining both the linear and nonlinear anomalous Hall effects. Yet in PT-symmetric antiferromagnetic metals, Hall effects from either intrinsic Berry curvature mediated anomalous velocity or the conventional skew-scattering process individually vanish. Here we reveal an unexpected nonlinear Hall effect that relies on both Berry curvature and skew-scattering working in cooperation. This anomalous skew-scattering nonlinear Hall effect (ASN) is PT even and dominates the low-frequency nonlinear Hall effect for PT-symmetric antiferromagnetic metals. Surprisingly, we find that in addition to its Hall response, ASN produces helicity dependent photocurrents, in contrast to other known PT-even nonlinearities in metals that are helicity blind. This characteristic enables us to isolate ASN and establishes new photocurrent tools to interrogate the antiferromagnetic order of PT-symmetric metals.
贝里曲率和斜散射在确定线性和非线性反常霍尔效应中都起着核心作用。然而，在宇称-时间（PT）对称反铁磁金属中，由本征贝里曲率介导的反常速度或传统斜散射过程单独产生的霍尔效应都会消失。在此，我们揭示了一种意想不到的非线性霍尔效应，它依赖于贝里曲率和斜散射的协同作用。这种反常斜散射非线性霍尔效应（ASN）是PT偶数的，并且在PT对称反铁磁金属的低频非线性霍尔效应中占主导地位。令人惊讶的是，我们发现除了其霍尔响应外，ASN还会产生与螺旋度相关的光电流，这与金属中其他已知的PT偶数非线性效应不同，后者对螺旋度不敏感。这一特性使我们能够分离出ASN，并建立新的光电流工具来探究PT对称金属的反铁磁序。
