Observation of chiral edge transport in a rapidly-rotating quantum gas

Abstract

The frictionless, directional propagation of particles at the boundary of topological materials is one of the most striking phenomena in transport. These chiral edge modes lie at the heart of the integer and fractional quantum Hall effects, and their extraordinary robustness against noise and disorder reflects the quantization of Hall conductivity in these systems. Despite their central importance, controllable injection of edge modes, and direct imaging of their propagation, structure, and dynamics, is challenging. Here, we demonstrate the distillation of individual chiral edge states in a rapidly-rotating bosonic superfluid confined by an optical boundary. Tuning the wall sharpness, we reveal the smooth crossover between soft wall behaviour in which the propagation speed is proportional to wall steepness, and the hard wall regime exhibiting chiral free particles. From the skipping motion of atoms along the boundary, we spectroscopically infer the energy gap between the ground and first excited edge bands, and reveal its evolution from the bulk Landau level splitting for a soft boundary, to the hard wall limit.

9 pages, 5+2 figures, v3 added a new figure

References in corpus (9)

• Topological Photonics
• Measuring the Chern number of Hofstadter bands with ultracold bosonic atoms
• Tunable gauge potential for neutral and spinless particles in driven lattices
• Observation of neutral modes in the fractional quantum Hall regime
• Crystallization of Bosonic Quantum Hall States
• Real-space imaging of quantum Hall effect edge strips
• Real-space detection and manipulation of topological edge modes with ultracold atoms
• Realization of an atomic quantum Hall system in four dimensions
• Mapping quantum Hall edge states in graphene by scanning tunneling microscopy

Cited by in corpus (10)

• Local probe of bulk and edge states in a fractional Chern insulator
• Emergent Fracton Hydrodynamics of Ultracold Atoms in Partially Filled Landau Levels
• Topological Chiral Edge States in a Synthetic Dimension of Atomic Trap States
• Wave-function microscopy: Derivation and anatomy of exact algebraic spinful wave functions and full Wigner-molecular spectra of a few highly correlated rapidly rotating ultracold fermionic atoms
• Anomalous wave-packet transport on boundaries of Floquet topological systems
• Rotating anisotropic Bose gas with large number of vortices
• Vortex and fractional quantum Hall phases in a rotating anisotropic Bose gas
• Dynamics of transport by helical edge states
• Quantum Hall edges beyond the plasma analogy
• Vorticity-Crystalline Order Coupling in Supersolids: Excitations and Re-entrant Phases