In Situ Epitaxy of Pure Phase Ultra-Thin InAs-Al Nanowires for Quantum Devices

Abstract

Hybrid semiconductor-superconductor InAs-Al nanowires with uniform and defect-free crystal interfaces are one of the most promising candidates used in the quest for Majorana zero modes (MZMs). However, InAs nanowires often exhibit a high density of randomly distributed twin defects and stacking faults, which result in an uncontrolled and non-uniform InAs-Al interface. Furthermore, this type of disorder can create potential inhomogeneity in the wire, destroy the topological gap, and form trivial sub-gap states mimicking MZM in transport experiments. Further study shows that reducing the InAs nanowire diameter from growth can significantly suppress the formation of these defects and stacking faults. Here, we demonstrate the in situ growth of ultra-thin InAs nanowires with epitaxial Al film by molecular-beam epitaxy. Our InAs diameter (~ 30 nm) is only one-third of the diameters (~ 100 nm) commonly used in literatures. The ultra-thin InAs nanowires are pure phase crystals for various different growth directions, suggesting a low level of disorder. Transmission electron microscopy confirms an atomically sharp and uniform interface between the Al shell and the InAs wire. Quantum transport study on these devices resolves a hard induced superconducting gap and $2e^{-}$ periodic Coulomb blockade at zero magnetic field, a necessary step for future MZM experiments. A large zero bias conductance peak with a peak height reaching 80% of $2e^2/h$ is observed.

arXiv comment36 pages, 20 figures

References in corpus (48)

• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Unpaired Majorana fermions in quantum wires
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Helical liquids and Majorana bound states in quantum wires
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• Observation of Majorana Fermions in a Nb-InSb Nanowire-Nb Hybrid Quantum Device
• Observation of the fractional ac Josephson effect: the signature of Majorana particles
• Exponential Protection of Zero Modes in Majorana Islands
• Majorana bound states in a coupled quantum-dot hybrid-nanowire system
• Realizing Majorana zero modes in superconductor-semiconductor heterostructures
• Superconductor-Nanowire Devices from Tunneling to the Multichannel Regime: Zero-Bias Oscillations and Magnetoconductance Crossover
• Spin-resolved Andreev levels and parity crossings in hybrid superconductor-semiconductor nanostructures
• Epitaxy of Semiconductor-Superconductor nanowires
• Scaling of Majorana Zero-Bias Conductance Peaks
• Andreev bound states versus Majorana bound states in quantum dot-nanowire-superconductor hybrid structures: Trivial versus topological zero-bias conductance peaks
• Hard gap in epitaxial semiconductor-superconductor nanowires
• Near-zero-energy end states in topologically trivial spin-orbit coupled superconducting nanowires with a smooth confinement
• Transport spectroscopy of NS nanowire junctions with Majorana fermions
• Towards a realistic transport modeling in a superconducting nanowire with Majorana fermions
• Ballistic Majorana nanowire devices
• Reproducing topological properties with quasi-Majorana states
• Ballistic superconductivity in semiconductor nanowires
• Two terminal charge tunneling: Disentangling Majorana zero modes from partially separated Andreev bound states in semiconductor-superconductor heterostructures
• Majorana bound states in non-homogeneous semiconductor nanowires
• Next steps of quantum transport in Majorana nanowire devices
• Disorder-induced zero-bias peaks in Majorana nanowires
• Soft Superconducting Gap in Semiconductor Majorana Nanowires
• Hard superconducting gap in InSb nanowires
• Effects of gate-induced electric fields on semiconductor Majorana nanowires
• Enhanced zero-bias Majorana peak in disordered multi-subband quantum wires
• Hybridization at superconductor-semiconductor interfaces
• Selective Area Grown Semiconductor-Superconductor Hybrids: A Basis for Topological Networks
• Zero-field Topological Superconductivity in Ferromagnetic Hybrid Nanowires
• Electric field tunable superconductor-semiconductor coupling in Majorana nanowires
• Effective theory approach to the Schrodinger-Poisson problem in semiconductor Majorana devices
• Engineering Hybrid Epitaxial InAsSb/Al Nanowire Materials for Stronger Topological Protection
• Epitaxial Pb on InAs nanowires
• Shadow-wall lithography of ballistic superconductor-semiconductor quantum devices
• Shadow epitaxy for in-situ growth of generic semiconductor/superconductor devices
• Selective-area chemical beam epitaxy of in-plane InAs one-dimensional channels grown on InP(001), InP(111)B, and InP(110) surfaces
• Conductance of a superconducting Coulomb blockaded Majorana nanowire
• Single-electron transport in InAs nanowire quantum dots formed by crystal phase engineering
• Decays of Majorana or Andreev oscillations induced by steplike spin-orbit coupling
• MBE Growth of Al/InAs and Nb/InAs Superconducting Hybrid Nanowire Structures
• Measurements of the spin-orbit interaction and Landé g factor in a pure-phase InAs nanowire double quantum dot in the Pauli spin-blockade regime
• Superconducting proximity effect in semiconductor nanowires

Cited by in corpus (20)

• Plateau regions for zero-bias peaks within 5% of the quantized conductance value $2e^2/h$
• Large zero bias peaks and dips in a four-terminal thin InAs-Al nanowire device
• Recent progress on Majorana in semiconductor-superconductor heterostructures--Engineering and detection
• Proximity effect in PbTe-Pb hybrid nanowire Josephson junctions
• Gatemon qubit based on a thin InAs-Al hybrid nanowire
• Quantifying quantum coherence of multiple-charge states in tunable Josephson junctions
• Hard superconducting gap in PbTe nanowires
• Microwave-assisted unidirectional superconductivity in Al-InAs nanowire-Al junctions under magnetic fields
• Large Andreev bound state zero bias peaks in a weakly dissipative environment
• Majorana corner modes and flat-band Majorana edge modes in superconductor/topological-insulator/superconductor junctions
• Gate-Compatible Circuit Quantum Electrodynamics in a Three-Dimensional Cavity Architecture
• Reducing disorder in PbTe nanowires for Majorana research
• Quantized Andreev conductance in semiconductor nanowires
• Josephson diode effect in nanowire-based Andreev molecules
• In situ tuning of dynamical Coulomb blockade on Andreev bound states in hybrid nanowire devices
• Theoretical proposal to obtain strong Majorana evidence from scanning tunneling spectroscopy of a vortex with a dissipative environment
• Enhanced superconductivity in PbTe-In hybrids
• Gate-tunable negative differential conductance in hybrid semiconductor-superconductor devices
• Ubiquitous missing first Shapiro step in Al-InSb nanosheet Josephson junctions
• Coulomb blockade in open superconducting islands on InAs nanowires