Quantum cascade of correlated phases in natural bilayer graphene

Diverging density of states can lead to correlated phases in low dimensional systems. This includes the graphene family that hosts electric-field controlled Lifshitz transitions and concomitant van Hove singularities in the density of states. Here, we present the observation of experimental signatures consistent with various interaction-driven phases in AB bilayer graphene including the fractional metals of Stoner type [1-3]. More prominently, we have found competing phases that exhibit intriguing temperature dependences and nonlinear I-V characteristics at zero magnetic field [1]. Evidencing interacting physics in this simple and reproducible system offers a fertile ground for exploring intricating many-body phases and for controlling quantum phase transitions, which can be leveraged to unravel dissipation pathways in correlated graphene systems.

[1] A. M. Seiler, F. R. Geisenhof, F. Winterer, K. Watanabe, T. Taniguchi, T. Xu, F. Zhang and R.T. Weitz, Nature 608, 298–302 (2022)

[2] H. Zhou, Y. Saito, L. Cohen, W. Huynh, C. L. Patterson, F. Yang, T. Taniguchi, K. Watanabe and A. F. Young, Science 375, 6582 (2022)

[3] S. C. de la Barrera, S. Aronson, Z. Zheng, K. Watanabe, T. Taniguchi, Q. Ma, P. Jarillo-Herrero and R. Ashoori, Nature Physics 18, 771-775 (2022)