# Moir\'e ordered current loops in the graphene twist bilayer

## TL;DR

This paper reveals that twisted bilayer graphene under a magnetic field hosts an ordered array of persistent current loops across the material, driven by moiré patterns and broken time-reversal symmetry.

## Contribution

It demonstrates the existence of moiré-scale current loops in twisted bilayer graphene under magnetic fields, a novel intrinsic feature linked to the moiré pattern and broken time-reversal symmetry.

## Key findings

- Current loops form throughout the material at small magnetic fields.
- Current loops exist in non-equilibrium transport states, flowing against bias.
- The loops are tied to the moiré pattern and broken time-reversal symmetry.

## Abstract

While a typical material exhibits field induced currents only at the boundary, a uniform out-of-plane magnetic field applied to two mutually rotated layers of graphene is shown to result in an ordered array of permanent current loops throughout the material. Each current loop consists of an interlayer current flowing through the open AA stacked regions of the moir\'e created by rotation, which then flows back through the neighboring AB regions to form a circuit, with significant current strength even at small fields. Similar moir\'e ordered arrays of current loops are also shown to exist in non-equilibrium transport states, where they manifest as current back flowing against the applied bias in the device. Such current loops thus represent an intrinsic feature of the twist bilayer in conditions of broken time reversal symmetry, and exist both as a low field imprint of the moir\'e lattice on Landau physics, and as measurable moir\'e scale current configurations in transport states.