Suppression of bulk conductivity in InAs/GaSb broken gap composite quantum wells

Abstract

The two-dimensional topological insulator state in InAs/GaSb quantum wells manifests itself by topologically protected helical edge channel transport relying on an insulating bulk. This work investigates a way of suppressing bulk conductivity by using gallium source materials of different degrees of impurity concentrations. While highest-purity gallium is accompanied by clear conduction through the sample bulk, intentional impurity incorporation lead to a bulk resistance over 1 MΩ. This resistance was found to be independent of applied magnetic fields. Ultra high electron mobilities for GaAs/AlGaAs structures fabricated in a molecular beam epitaxy system used for the growth of Sb-based samples are reported.

References in corpus (4)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Quantum Spin Hall Effect in Inverted Type II Semiconductors
• Edge Channel Transport in InAs/GaSb Topological Insulating Phase

Cited by in corpus (21)

• Observation of Quantum Spin Hall States in InAs/GaSb Bilayers under Broken Time-Reversal Symmetry
• Edge-mode Superconductivity in a Two Dimensional Topological Insulator
• Images of edge current in InAs/GaSb quantum wells
• Edge Transport in the Trivial Phase of InAs/GaSb
• Nuclear-spin-induced localization of the edge states in two-dimensional topological insulators
• Effects of nuclear spins on the transport properties of the edge of two-dimensional topological insulators
• Insulating state and giant non-local response in an InAs/GaSb quantum well in the quantum Hall regime
• Non-local transport via edge-states in InAs/GaSb coupled quantum wells
• Edge transport in InAs and InAs/GaSb quantum wells
• Gate-controlled semimetal-topological insulator transition in an InAs/GaSb heterostructure
• Decoupling edge versus bulk conductance in the trivial regime of an InAs/GaSb double quantum well using Corbino ring geometry
• Helical Liquids in Semiconductors
• Massless Dirac fermions in III-V semiconductor quantum wells
• Energy gap tuning and gate-controlled topological phase transition in InAs/In${}_x$Ga${}_{1-x}$Sb composite quantum wells
• Spin-orbit interaction in InAs/GaSb heterostructures quantified by weak antilocalization
• Rashba Sandwiches with Topological Superconducting Phases
• Circular and Linear Photogalvanic Effects in Type-II GaSb/InAs Quantum Well Structures in the Inverted Regime
• Localization of trivial edge states in InAs/GaSb composite quantum wells
• On the impact of strain on the electronic properties of InAs/GaSb quantum well systems
• Impact of epitaxial strain on the topological-nontopological phase diagram and semimetallic behavior of InAs/GaSb composite quantum wells
• Disorder effects in InAs/GaSb topological insulator candidates