Clean quantum point contacts in an InAs quantum well grown on a lattice-mismatched InP substrate

Abstract

Strong spin-orbit coupling, the resulting large $g$ factor, and small effective mass make InAs an attractive material platform for inducing topological superconductivity. The surface Fermi level pinning in the conduction band enables highly transparent ohmic contact without excessive doping. We investigate electrostatically defined quantum point contacts (QPCs) in a deep-well InAs two-dimensional electron gas. Despite the 3.3% lattice mismatch between the InAs quantum well and the InP substrate, we report clean QPCs with up to eight pronounced quantized conductance plateaus at zero magnetic field. Source-drain dc bias spectroscopy reveals a harmonic confinement potential with a nearly $5$ meV subband spacing. We find a many-body exchange interaction enhancement for the out-of-plane $g$ factor $|g_{\perp }^{\ast }|=27\pm 1$, whereas the in-plane $g$ factor is isotropic $|g_x^{\ast }|=|g_y^{\ast }|=12\pm 2$, close to the bulk value for InAs.

Main text (8 pages, 5 figures), Supplemental Material (10 pages, 10 figures)

References in corpus (12)

• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Single-shot read-out of an individual electron spin in a quantum dot
• Majorana bound states in a coupled quantum-dot hybrid-nanowire system
• Circuit Quantum Electrodynamics with a Spin Qubit
• Fast Single-Charge Sensing with an rf Quantum Point Contact
• Quantized conductance and large g-factor anisotropy in InSb quantum point contacts
• Edge transport in InAs and InAs/GaSb quantum wells
• $h/e$ superconducting quantum interference through trivial edge states in InAs
• Gating of high-mobility InAs metamorphic heterostructures
• An apparent metal insulator transition in high mobility 2D InAs heterostructures
• Few-electron Single and Double Quantum Dots in an InAs Two-Dimensional Electron Gas
• Magnetic Field Inducing Zeeman Splitting and Anomalous Conductance Reduction of Half-integer Quantized Plateaus in InAs Quantum Wires