Coexisting edge states and gapless bulk in topological states of matter

Abstract

We consider two dimensional systems in which edge states coexist with a gapless bulk. Such systems may be constructed, for example, by coupling a gapped two dimensional state of matter that carries edge states to a gapless two dimensional system in which the spectrum is composed of a number of Dirac cones. We find that in the absence of disorder the edge states could be protected even when the two systems are coupled, due to momentum and energy conservation. We distinguish between weak and strong edge states by the level of their mixing with the bulk. In the presence of disorder, the edge states may be stabilized when the bulk is localized or destabilized when the bulk is metallic. We analyze the conditions under which these two cases occur. Finally, we propose a concrete physical realization for one of our models on the basis of bilayer Hg(Cd)Te quantum wells.

7 pages, 9 figures

References in corpus (7)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Classification of topological insulators and superconductors in three spatial dimensions
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Quantum Spin Hall Effect in Inverted Type II Semiconductors
• Single valley Dirac fermions in zero-gap HgTe quantum wells

Cited by in corpus (11)

• Evidence of topological Shiba bands in artificial spin chains on superconductors
• Helical Liquids in Semiconductors
• Antiferromagnetism-driven two-dimensional topological nodal-point superconductivity
• Two-dimensional topological insulator state in double HgTe quantum well
• Engineering topological phases in triple HgTe/CdTe quantum wells
• Longitudinal DC Conductivity in Dirac Nodal Line Semimetals: Intrinsic and Extrinsic Contributions
• Stacking-Induced Symmetry-Protected Topological Phase Transitions
• Exotic surface states in hybrid structures of topological insulators and Weyl semimetals
• Proximity-induced zero-energy states indistinguishable from topological edge states
• Helical Topological Superconducting Pairing at Finite Excitation Energies
• Topology and edge modes surviving criticality in non-Hermitian Floquet systems