Observation of competing, correlated ground states in the flat band of rhombohedral graphite

• DOI: 10.1126/sciadv.abo6879
• Publication Date: 2022-09-02T17:58:24Z
• Authors: Imre Hagymási; Mohammad Syahid M...; Zoltán Tajkov; Krisztián Márity; László Oroszlány; János Koltai; Assem Alassaf; Péter Kun; Konrád Kandrai; András Pálinkás; Péter Vancsó; Levente Tapasztó; Péter Nemes-Incze
• Keywords: Trigonal crystal system

In crystalline solids, the interactions of charge and spin can result in a variety emergent quantum ground states, especially partially filled, topological flat bands such as Landau levels or “magic angle” graphene layers. Much less explored is rhombohedral graphite (RG), perhaps simplest structurally most perfect condensed matter system to host band protected by symmetry. By scanning tunneling microscopy, we map density 8, 10, 14, 17 layers identify domain structure emerging from competition between sublattice antiferromagnetic insulator gapless correlated paramagnet. Our matrix renormalization group calculations explain observed features demonstrate that correlations are fundamentally different graphene-based magnetism identified until now, forming state magnet. work establishes RG platform study many-body beyond mean-field approach, where fluctuations entanglement dominate.