Correlated Interlayer Quantum Hall State in Large-Angle Twisted Trilayer Graphene

Abstract

Trilayer graphene offers systematic control of its electronic structure through the stacking sequence and twist geometry, providing a versatile platform for correlated states. Here we report magnetotransport in a large-angle twisted trilayer graphene with a twist angle of about 5 degrees. The data reveal an electron-hole asymmetry that can be captured by introducing layer-dependent potential shifts. At charge neutrality (nu tot = 0), three low-resistance states appear, which Hartree-Fock mean-field analysis attributes to spin-resolved helical edge modes in the quantum Hall regime, analogous to quantum spin Hall-like configurations. At nu tot = -1, we also observe suppressed resistance when the middle and bottom layers are each half filled, while the top layer remains inert at nu = -2, consistent with an interlayer excitonic phase in the quantum Hall regime. These results demonstrate correlated interlayer quantum Hall phases in large-angle twisted trilayer graphene by combining spin-resolved helical edge transport with excitonic order.