Electrically tunable heavy fermion and quantum criticality in magic-angle twisted trilayer graphene
Abstract
The interplay between localized magnetic moments and itinerant electrons gives rise to exotic quantum states in condensed matter systems. Two-dimensional moire superlattices offer a powerful platform for engineering heavy fermion states beyond conventional rare-earth intermetallic compounds. While localized and itinerant carriers have been observed in twisted graphene moire systems, direct evidence of their strong coupling--leading to artificial heavy fermion states--has remained elusive. Here, we demonstrate electrically tunable heavy fermion in magic-angle twisted trilayer graphene, achieved by controlling the Kondo hybridization between localized flatband electrons and itinerant Dirac electrons via a displacement field. Our results reveal a continuous quantum phase transition from an antiferromagnetic semimetal to a paramagnetic heavy fermion metal, evidenced by a crossover from logarithmic to quadratic temperature-dependent resistivity, a dramatic enhancement of quasiparticle effective mass, and Fermi surface reconstruction near quantum critical point. This highly tunable platform offers unprecedented control over heavy fermion physics, establishing moire heterostructures as a versatile arena for exploring correlated quantum phases--including potential unconventional superconductivity--in two-dimensional materials.
Keywords
Cite
@article{arxiv.2507.12254,
title = {Electrically tunable heavy fermion and quantum criticality in magic-angle twisted trilayer graphene},
author = {Le Zhang and Wenqiang Zhou and Xinjie Fang and Zhen Zhan and Kenji Watanabe and Takashi Taniguchi and Yi-feng Yang and Shuigang Xu},
journal= {arXiv preprint arXiv:2507.12254},
year = {2025}
}