Experimental realization of chiral Landau levels in two-dimensional Dirac cone systems with inhomogeneous effective mass

TL;DR

This paper demonstrates the theoretical proposal and experimental observation of chiral Landau levels in two-dimensional Dirac systems using a photonic setup with inhomogeneous effective mass, highlighting robust one-way transport.

Contribution

It introduces a novel method to realize chiral Landau levels in 2D Dirac systems through inhomogeneous mass, previously only studied in 3D Weyl systems.

Findings

Experimental observation of chiral zeroth Landau levels in 2D photonic systems.

Robust one-way transport of chiral modes against defects.

Potential applications in device design leveraging transport robustness.

Abstract

Chiral zeroth Landau levels are topologically protected bulk states that give rise to chiral anomaly. Previous discussions on such chiral Landau levels are based on three-dimensional Weyl degeneracies. Their realizations using two-dimensional Dirac point systems, being more promising for future applications, were never reported before. Here we propose a theoretical and experimental scheme for realizing chiral Landau levels in a photonic system. By introducing an inhomogeneous effective mass through breaking local parity inversion symmetries, the zeroth-order chiral Landau levels with one-way propagation characteristics are experimentally observed. In addition, the robust transport of the chiral zeroth mode against defects in the system is experimentally tested. Our system provides a new pathway for the realization of chiral Landau levels in two-dimensional Dirac systems, and may potentially be applied in device designs utilizing the transport robustness.