报告题目：Superconductivity in Graphene Heterostructures

报 告 人：Pierre A. Pantaleón

报告时间：2025年9月23日14：00

报告地点：物理楼W105

内容摘要：Graphene heterostructures host narrow bands and strong interactions that enable unconventional superconductivity (SC). Beyond magic-angle twisted bilayer graphene (TBG), SC has also been reported in other twisted multilayers and recently in non-twisted rhombohedral multilayer graphene, raising the question of a unifying mechanism. We investigate these systems within a Kohn–Luttinger–like, Random Phase Approximation (KL-RPA) framework and show that, in twisted structures, the critical temperature depends strongly on wavefunction localization. In TBG, extended states promote Umklapp scattering and yield Tc around 6 K, whereas localization in other twisted multilayers suppresses pairing to the millikelvin regime. The Hartree potential, tied to charge redistribution in flat bands, further modulates pairing strength; together with wavefunction localization, it provides a predictive mechanism for SC in twisted heterostructures. Comparisons with non-twisted rhombohedral multilayers, where Tc is also in the millikelvin range, reveal common features in the superconducting state, suggesting continuity across twisted and untwisted systems. Our results position the KL-RPA framework as a robust candidate theory for superconductivity in graphitic compounds and highlight strategies to engineer higher Tc in these materials.

报告人简介：Pierre A. Pantaleón is a theoretical physicist with international experience in quantum materials and low dimensional systems. He earned a PhD in Physics from the University of Manchester, where he studied topological properties of magnetic spin lattices, and holds master and bachelor degrees in Theoretical and Mathematical Physics from the Universidad Autónoma de Baja California, with training in applied mathematics at the Universidad de Cádiz. He has taught as a university lecturer and coordinated science museum workshops. Dr. Pantaleón is a principal researcher at IMDEA Nanoscience in Madrid in theoretical modelling. His research focuses on electronic correlations, superconductivity, and topological phenomena in graphene heterostructures. He develops analytical models, continuum approaches, and large scale simulations to study twisted and untwisted graphene multilayers, artificial moiré superlattices, and interaction driven phases. Recent work introduced a generalized KL RPA (Kohn Luttinger Random Phase Approximation) framework to predict superconductivity in graphene heterostructures and proposes device level strategies using artificial superlattices to engineer correlated states. He has authored peer reviewed publications in journals such as Nature Reviews Physics, Nature Communications, ACS Nano, Physical Review Letters, and PNAS, and maintains active collaborations with teams across China, Mexico, the United States, Singapore, Argentina, and Europe.