Persistent current and orbital magnetization along a valley-contrasting junction in bilayer graphene in a magnetic field
Phys. Rev. B 113, 235422 – Published 16 June, 2026
DOI: https://doi.org/10.1103/wcv4-j7gd
Abstract
In a magnetic field, bilayer graphene hosts an octet of pseudo-zero-mode (PZM) electron levels nearly degenerate in orbitals , valleys, and spins. They split in valleys by electrostatic gating. In gated bilayer graphene, in which the interlayer bias is set up to flip sign across a line, one has a line junction that traps a portion of PZM electrons inside the insulating bulk band gap, giving rise to electron states localized along the junction, known as kink states. A close look is made into the spectra and electromagnetic response of such kink states. There are two species of valley current associated with them, a drift current driven by the bias gradient and a circulating current coming from cyclotron motion. It turns out that they both flow in essentially the same direction, with the circulating current exhibiting a magnetic character distinct from those of other higher levels. In equilibrium, they spatially circulate within the kink states, creating a quasi-one-dimensional channel of orbital magnetization. The electric control of the orbital magnetization and valley currents via a network of gated junctions will find useful applications in valley electronics.