Fractional Quantum Hall Effect in Trilayer Graphene Proximitized by V-Doped WSe₂

Graphene is a suitable platform for observing strongly correlated phenomena resulting from its two-dimensional nature and ability to host high carrier mobility. Nevertheless, the lack of intrinsic magnetism and weak spin-orbit coupling have limited its ability to host strong electronic correlations. Here, we report the observation of strongly correlated phenomena in trilayer graphene (TLG) proximitized by a ferromagnetic V-doped WSe₂ (V-WSe₂) overlayer. These include the emergence of an even-denominator (5/2) fractional quantum Hall states and reentrant integer quantum Hall states in the hole regime of TLG. The strong correlations in the TLG are driven by proximate magnetism from the V-WSe₂. Furthermore, we observe the formation of three additional Dirac cones in the TLG, termed Dirac “gullies”, which are seen as threefold-degenerate Landau levels in magneto-transport measurements. These findings not only advance our understanding of strongly correlated phenomena in graphene-based heterostructures but also pave the way towards novel quantum materials engineering.