Charge ordering and fractionalization in rhombohedral multilayer graphene

In quantum Hall systems, Coulomb interactions stabilize two competing forms of order: fractional quantum Hall (FQH) liquids and charge-density-wave (CDW) states. A phase in which the two coexist, the fractional Hall crystal, has long been envisioned but has remained elusive. Here, using bulk and edge transport measurements, we study semimetallic rhombohedral multilayer graphene in quantizing magnetic fields and uncover an extended family of fractional Hall crystals. Charge ordering strongly violates the correspondence between filling factor and Hall conductance that holds for a translationally invariant quantum Hall liquid. Most notably, we observe fractionally quantized Hall plateaus at integer Landau-level fillings. The conventional Jain sequences are also absent. Instead, which fractional states appear, and how stable they are, is set by the underlying charge order. These observations reveal a regime in which electron crystallization reorganizes fractionalization rather than simply competing with it. They establish rhombohedral graphene as a platform for fractional Hall crystals without a moiré superlattice.