Even Denominator Fractional Quantum Hall States in the Zeroth Landau Level of ABA Trilayer Graphene

Even-denominator fractional quantum Hall states at half-filling are of particular interest because they can host non-Abelian quasiparticles. Here, we report the emergence of such states in the zeroth Landau level (N=0) of ABA trilayer graphene (TLG), challenging the conventional expectation that they are confined to the first excited Landau level. We observe robust incompressible states at ν=7/2, 9/2, and 5/2 with their associated Levin-Halperin daughter states: ν=59/17 and 46/13 near 7/2; ν=58/13 and 77/17 near 9/2; and ν=43/17 near 5/2. These states appear exclusively within a finite displacement-field window coincident with crossings between symmetry-broken N=0 Landau levels carrying distinct isospin indices. The quantitative correspondence between the calculated crossing loci and the experimentally determined stability regions identifies Landau-level mixing as the microscopic origin. We attribute the stabilization of these even-denominator states to inversion-symmetry breaking in TLG, which enhances valley-resolved Landau-level hybridization and renormalizes short-range Coulomb interactions. Our results expand the landscape of even-denominator fractional quantum Hall states to multilayer graphene and establish TLG as a tunable platform for realizing non-Abelian anyons.