Valleytronics in 2D Materials Roadmap

TL;DR

This roadmap reviews recent advances and future prospects in valleytronics within 2D materials, highlighting progress, challenges, and opportunities for encoding and manipulating information using valley degrees of freedom.

Contribution

It provides a comprehensive overview of the current state, key research areas, and future directions in 2D material valleytronics, integrating expert perspectives.

Findings

Progress in valley exciton physics and valley Hall effects

Emerging directions like lightwave valleytronics and spin-valley qubits

Identification of key challenges and pathways for future breakthroughs

Abstract

Valleytronics exploits non-equivalent energy extrema in the electronic band structure of crystalline solids -- the valley degree of freedom -- to encode, manipulate, and read out information. The advent of 2D materials, first graphene and then transition-metal dichalcogenides, made valley control practical through optical, electrical, and magnetic routes. This foundation has enabled remarkable progress in recent years spanning established frontiers, such as valley exciton physics and valley Hall effects, as well as emerging directions including lightwave valleytronics, nanophotonic integration, flat-band valleytronics, and spin-valley qubits. In parallel, there are sustained efforts to scale up valleytronic materials and to predict new valleytronic platforms. This Roadmap brings together perspectives from leading experts to chart the key opportunities and challenges at the forefront of 2D material valleytronics. Each section captures a snapshot of progress in a key research area, identifies critical open challenges, and outlines pathways toward future valleytronics breakthroughs.