vix.ing · top · new · best · stats

Giant Second-Order Nonlinear Hall Effect in Twisted Bilayer Graphene

2022/10/24 by Junxi Duan, Yu Jian, Yang Gao +6 · 98 citations
Chemistry · Materials Science · Physics and Astronomy · #Bilayer #Bilayer graphene #Business #Chemistry #Condensed matter physics #Graphene #Graphene research and applications #Materials science #Membrane #Nanotechnology #Nonlinear system #Order (exchange) #Physics #Quantum and electron transport phenomena #Quantum mechanics #Topological Materials and Phenomena

paper · doi:10.1103/physrevlett.129.186801

published in Physical Review Letters 129(18), 186801 (American Physical Society)

openalex publication_date 2022/10/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

In the second-order response regime, the Hall voltage can be nonzero without time-reversal symmetry breaking but inversion symmetry breaking. Multiple mechanisms contribute to the nonlinear Hall effect. The disorder-related contributions can enter the NLHE in the leading role, but experimental investigations are scarce, especially the exploration of the contributions from different disorder sources. Here, we report a giant nonlinear response in twisted bilayer graphene, dominated by disorder-induced skew scattering. The magnitude and direction of the second-order nonlinearity can be effectively tuned by the gate voltage. A peak value of the second-order Hall conductivity reaching 8.76 μm SV-1 is observed close to the full filling of the moiré band, four order larger than the intrinsic contribution detected in WTe2. The scaling shows that the giant second-order nonlinear Hall effect in twisted bilayer graphene stems from the collaboration of the static (impurities) and dynamic (phonons) disorders. It is mainly determined by the impurity skew scattering at 1.7 K. The phonon skew scattering, however, has a much larger coupling coefficient, and becomes comparable to the impurity contribution as the temperature rises. Our observations provide a comprehensive experimental understanding of the disorder-related mechanisms in the nonlinear Hall effect.

Citations

Cited by

Related