A complete understanding of nonlinear Hall effect: from Berry-curvature dipole to magnetic-field dipole. Ching-Hao Chang ^{1,2*}, Botsz Huang^{1,2}, Sheng-Chin Ho^{1,2}, Ali G. Moghaddam^{3}, Jorge I. Facio^{3}, Tse-Ming Chen^{1,2}^{1}Department of Physics, National Cheng Kung University, Tainan, Taiwan^{2}Center for Quantum Frontiers of Research and Technology (QFort), National Cheng Kung University, Tainan, Taiwan^{3}Institute for Theoretical Solid State Physics, IFW Dresden, Dresden, Germany* Presenter:Ching-Hao Chang, email:cutygo@phys.ncku.edu.tw In this talk, we will introduce our recent works including realize and create nonlinear Hall effect (NLHE) in nanoarchitectures. In pioneer studies, the NLHE is predicted and observed in nonmagnetic material with ultra-low lattice symmetry [1, 2]. This effect is induced by the dipole of effective magnetic field in the momentum space, namely the Berry curvature dipole [1]. Our collaborative work, however, opens up an avenue to create NLHE in artificially corrugated two-dimensional electron system [3]. We confirm the created NLHE in the corrugated graphene system can be even an order of magnitude larger than that in low-lattice-symmetry materials [3]. Recently, we further predict that NLHE can be induced by the applied magnetic-field dipole [4]. We thus provide a complete picture of NLHE - this second-order Hall effect can be driven either by the magnetic-field dipole in real space or in momentum space. We expect this new NLHE will be measured in the experiment, and pave a new way to engineer current rectification and higher harmonic generation in two-dimensional materials.
[1] I. Sodemann and L. Fu, Phys. Rev. Lett. 115, 216806 (2015). [2] Q. Ma, S.-Y. Xu, H. Shen, D. MacNeill, V. Fatemi, T.-R. Chang, et. al., Nature 565, 337 (2019). [3] Sheng-Chin Ho, Ching-Hao Chang, Yu-Chiang Hsieh, Shun-Tsung Lo, Botsz Huang, Carmine Ortix, and Tse-Ming Chen Nature Electronics 4, 116 (2021). [4] Botsz Huang, Ali G. Moghaddam, Jorge I. Facio, and Ching-Hao Chang, Phys. Rev. B 104, 165303 (2021). Keywords: Hall effect, Berry curvature , two-dimensional electron system, magnetic field |