Classical spins in topological insulators

Abstract

Following the recent theoretical proposal and experiment on quantum spin Hall effect in HgTe/CdTe quantum wells, we consider a single magnetic impurity localized in the bulk of the system, which we treat as a classical spin. It is shown that there are always localized excited states in the bulk energy gap for arbitrarily strong impurity strength in inverted region, while the localized excited states vanish for very strong impurity strength in normal region. Similar conclusion also applies to three-dimensional topological insulators. This distinct difference serves as another novel criterion for the conventional and topological insulating phases when the time-reversal symmetry is broken, and can be easily experimentally observed through the STM and/or ARPES experiments.

5 pages, 4 figures.

References in corpus (16)

• Quantum Spin Hall Effect in Graphene
• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• $Z_2$ Topological Order and the Quantum Spin Hall Effect
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Insulators in Three Dimensions
• Topological Insulators with Inversion Symmetry
• Topological Field Theory of Time-Reversal Invariant Insulators
• Topological invariants of time-reversal-invariant band structures
• Quantum Spin Hall Effect
• Topological quantization of the spin Hall effect in two-dimensional paramagnetic semiconductors
• Quantum Anomalous Hall Effect in Hg${}_{1-y}$Mn${}_y$Te Quantum Wells
• Magnetic impurities on the surface of a topological insulator
• Band structure of semimagnetic Hg1-yMnyTe quantum wells
• On the $Z_2$ classification of Quantum Spin Hall Models
• Helical edge and surface states in HgTe quantum wells and bulk insulators

Cited by in corpus (6)

• Overscreened Kondo effect, (color) superconductivity and Shiba states in Dirac metals and quark matter
• Colossal anisotropy in diluted magnetic topological insulators
• Quantum impurity in the bulk of topological insulator
• Impurity-induced bound states in superconductors with topological order
• Tuning topological surface magnetism by bulk alloying
• Impurity-induced Mott ring states and Mott zeros ring states in the Hubbard operator formalism