Vanishing Hall Effect in the Epigraphene Zero Energy Edge State

Graphene's exceptional electronic properties have made it a longstanding candidate for a future generation of electronics, but disorder and high contact resistances hindered integration into current device architectures. Graphene grown epitaxially on silicon carbide (epigraphene) hosts a highly stable, protected edge state which survives harsh nanofabrication processes on both polar and non-polar facets [1]. We show here that the high density of states of the edge state pins the Fermi level at zero energy. We present experimental evidence of an unconventional single-channel edge state in epigraphene with a mean-free path larger than hundreds of microns even at room temperature, orders of magnitude larger than that of the bulk. The most unexpected feature is the absence of a Hall voltage, indicating an unpredicted fermionic quasiparticle that bears no charge but transports current. The edge state forms a one-dimensional network shunts the diffusive bulk states. We also show that this edge state can be branched, which demonstrates epigraphene’s potential for integration in networks including high-frequency circuits.



[1] Prudkovskiy, V.S. et al. Nat Comm 13, 7814 (2022).