Antichiral states in twisted graphene multilayers

TL;DR

This paper proposes a method to realize antichiral states in twisted graphene multilayers by combining moiré superstructures, magnetic fields, and bias voltages, enabling controlled engineering of these states in solid materials.

Contribution

It introduces a novel approach to generate antichiral states in twisted van der Waals heterostructures using specific experimental conditions.

Findings

Antichiral states can be realized in graphene/hBN multilayers at 8 T magnetic field.

A specific twist angle of 0.2° enables the emergence of antichiral states.

The method provides a controllable way to engineer antichiral states in solid-state systems.

Abstract

The advent of topological phases of matter revealed a variety of observed boundary phenomena, such as chiral and helical modes found at the edges of two-dimensional (2D) topological insulators. Antichiral states in 2D semimetals, i.e., copropagating edge modes on opposite edges compensated by a counterpropagating bulk current, are also predicted, but, to date, no realization of such states in a solid-state system has been found. Here, we put forward a procedure to realize antichiral states in twisted van der Waals multilayers, by combining the electronic Dirac-cone spectra of each layer through the combination of the orbital moir\'e superstructure, an in-plane magnetic field, and inter-layer bias voltage. In particular, we demonstrate that a twisted van der Waals heterostructure consisting of graphene/two layers of hexagonal boron nitride [(hBN)$_2$]/graphene will show antichiral states at in-plane magnetic fields of 8 T, for a rotation angle of 0.2$^{\circ}$ between the graphene layers. Our findings engender a controllable procedure to engineer antichiral states in solid-state systems, as well as in quantum engineered metamaterials.