The second-order nonlinear electrical response (NLER) is an intrinsic property of inversion symmetry-broken systems which can provide deep insights into the electronic band structures of atomically thin quantum materials. However, the impact of Fermi surface reconstructions, also known as Lifshitz transitions, on the NLER has remained elusive. We investigated NLER in bilayer graphene (BLG), where the low-energy bands undergo Lifshitz transitions. Here, NLER undergoes a sign change near the Lifshitz transitions even at elevated temperatures T≳10K. At the band edge, NLER in BLG is modulated by both extrinsic scattering and interfacial-strain-induced intrinsic Berry curvature dipole, both of which can be finely tuned externally by varying doping and interlayer potential. Away from the band edge, BLG exhibits second-order conductivity exceeding 30μmV−1Ω−1 at 3K higher than any previous report. Our work establishes NLER as a reliable tool to probe Lifshitz transitions in quantum materials.
@article{arxiv.2507.05871,
title = {Detecting Lifshitz Transitions Using Nonlinear Conductivity in Bilayer Graphene},
author = {Tanweer Ahmed and Harsh Varshney and Bao Q. Tu and Kenji Watanabe and Takashi Taniguchi and Marco Gobbi and Fèlix Casanova and Amit Agarwal and Luis E. Hueso},
journal= {arXiv preprint arXiv:2507.05871},
year = {2025}
}
Comments
This is the pre-peer reviewed version of the following article: Ahmed, T. et al., Small 2025, 21 (21), 2501426, which has been published in final form at https://doi.org/10.1002/smll.202501426. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions