PbTe/PbSnTe heterostructures as analogs of topological insulators

Abstract

We investigate theoretically the PbTe/PbSnTe heterostructure grown in [111] direction, specifically a quantum wall (potential step of width d) of PbTe embedded in Pb_{1-x}Sn_{x}Te. For x large enough to lead to band inversion, and for large d, there are well-known gapless interface states associated with four L valleys. We show that for d \approx\ 10 nm the three pairs of states from oblique valleys strongly couple, and become gapped with a gap ~10 meV. On the other hand, the interface states from the [111] valley are essentially uncoupled, and they retain their helical character, remaining analogous to states at surfaces of thin layers of three-dimensional topological insulators. This opens up a possibility of studying the physics of two-dimensional helical Dirac fermions in heterostuctures of already widely studied IV-VI semicondcutors.

6 pages, 4 figures, final version published in Phys. Rev. B

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• Universal phase diagrams for the quantum spin Hall systems
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Cited by in corpus (13)

• Topological crystalline insulator states in Pb(1-x)Sn(x)Se
• Surface States of Topological Crystalline Insulators in IV-VI Semiconductors
• The topological-crystalline-insulator (Pb,Sn)Te - surface states and their spin-polarization
• Weak Topological Insulators in PbTe/SnTe Superlattices
• Quantum Spin Hall Effect in IV-VI Topological Crystalline Insulators
• Fermi surface and electron dispersions of PbTe doped with resonant Tl impurity from KKR-CPA calculations
• Electrically Tunable Quantum Spin Hall State in Topological Crystalline Insulator Thin films
• Tunable Dirac interface states in topological superlattices
• Transport discovery of emerging robust helical surface states in $Z_2=0$ systems
• Absence of nonlocal resistance in microstructures of PbTe quantum wells
• Interaction between interface and massive states in multivalley topological heterostructures
• Miniband engineering and topological phase transitions in topological - normal insulator superlattices
• Robust midgap states in band-inverted junctions under electric and magnetic fields