Topological bulk states and their currents

Abstract

We provide evidence that, alongside topologically protected edge states, two-dimensional Chern insulators also support localised bulk states deep in their valance and conduction bands. These states manifest when local potential gradients are applied to the bulk, while all parts of the system remain adiabatically connected to the same phase. In turn, the bulk states produce bulk current transverse to the strain. This occurs even when the potential is always below the energy gap, where one expects only edge currents to appear. Bulk currents are topologically protected and behave like edge currents under external influence, such as temperature or local disorder. Detecting topologically resilient bulk currents offers a direct means to probe the localised bulk states.

arXiv comment12 pages, 8 figures

References in corpus (22)

• Topological Insulators
• Topological insulators and superconductors
• Quantum Spin Hall Effect in Graphene
• $Z_2$ Topological Order and the Quantum Spin Hall Effect
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Experimental realisation of the topological Haldane model
• Quantum Spin Hall Effect
• The (High Quality) Topological Materials In The World
• Topological orders and Edge excitations in FQH states
• Creating, moving and merging Dirac points with a Fermi gas in a tunable honeycomb lattice
• Towards ideal topological materials: Comprehensive database searches using symmetry indicators
• Topological Quantum Matter with Ultracold Gases in Optical Lattices
• Manipulation of Majorana fermion, Andreev reflection and Josephson current on topological insulators
• Experimental reconstruction of the Berry curvature in a topological Bloch band
• Measuring quantized circular dichroism in ultracold topological matter
• Tuning the conductance of Dirac fermions on the surface of a topological insulator
• Topological Materials Discovery By Large-order symmetry indicators
• Elasticity tetrads, mixed axial-gravitational anomalies, and 3+1d quantum Hall effect
• Tunneling Planar Hall Effect in Topological Insulators: Spin-Valves and Amplifiers
• Chiral Anomaly and Effective Field Theory for the Quantum Hall Liquid with Edges
• Haldane Model at finite temperature
• Seeing topological edge and bulk currents in time-of-flight images

Cited by in corpus (4)

• Chiral Interface States and Related Quantized Transport in Disordered Chern Insulators
• Nonreciprocal heat transport in the Kitaev chiral spin liquid
• Quantum spin Hall insulator in proximity with a superconductor: Transition to the Fulde-Ferrell-Larkin-Ovchinnikov state driven by a Zeeman field
• Seeing topological edge and bulk currents in time-of-flight images