A5073919442- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Physics of Superconductivity and Magnetism
- Nanowire Synthesis and Applications
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Quantum Structures and Devices
- Electronic and Structural Properties of Oxides
- Graphene research and applications
- Advanced Semiconductor Detectors and Materials
- 2D Materials and Applications
- Magnetic properties of thin films
- Quantum Information and Cryptography
- Semiconductor materials and devices
- Semiconductor materials and interfaces
- Mechanical and Optical Resonators
- Photonic and Optical Devices
- Surface and Thin Film Phenomena
- Intermetallics and Advanced Alloy Properties
- Geochemistry and Geologic Mapping
- Seismic Imaging and Inversion Techniques
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum Computing Algorithms and Architecture
- Magnetic and transport properties of perovskites and related materials
- GaN-based semiconductor devices and materials
- Advanced Condensed Matter Physics
Microsoft (United States)
2020-2025
Delft University of Technology
2018-2023
QuTech
2018-2023
Microsoft (Norway)
2020
Forschungszentrum Jülich
2012-2020
Eindhoven University of Technology
2020
Jülich Aachen Research Alliance
2013-2019
University of Regensburg
2016-2017
Stadtwerke Jülich (Germany)
2015
Topological phases of matter can enable highly stable qubits with small footprints, fast gate times, and digital control. These hardware-protected must be fabricated a material combination in which topological phase reliably induced. The challenge: disorder destroy the obscure its detection. This paper reports on devices low enough to pass gap protocol, thereby demonstrating gapped superconductivity paving way for new qubit.
Selective-area growth is a promising technique for enabling of the fabrication scalable III–V nanowire networks required to test proposals Majorana-based quantum computing devices. However, contours parameter window resulting in selective remain undefined. Herein, we present set experimental techniques that unambiguously establish space by molecular beam epitaxy. Selectivity maps are constructed both GaAs and InAs compounds based on situ characterization kinetics GaAs(001) substrates, where...
The realization of a topological qubit calls for advanced techniques to readily and reproducibly engineer induced superconductivity in semiconductor nanowires. Here, we introduce an on-chip fabrication paradigm based on shadow walls that offers substantial advances device quality reproducibility. It allows the implementation novel quantum devices ultimately qubits while eliminating many steps such as lithography etching. This is critical preserve integrity homogeneity fragile hybrid...
The number of electrons in small metallic or semiconducting islands is quantised. When tunnelling enabled via opaque barriers this can change by an integer. In superconductors the addition units two electron charges (2e), reflecting that Cooper pair condensate must have even parity. This ground state (GS) foundational for all superconducting qubit devices. Here, we study a hybrid superconducting-semiconducting island and find three typical GS evolutions parallel magnetic field: robust...
High aspect-ratio InSb nanowires (NWs) of high chemical purity are sought for implementing advanced quantum devices. The growth NWs is challenging, generally requiring a stem foreign material nucleation. Such tends to limit the length and its becomes incorporated in segment. Here, we report on chemically pure tens microns long. Using selective-area mask combination with gold as catalyst allows complete omission stem, thus demonstrating that can grow directly from substrate. introduction...
One-dimensional ballistic transport is demonstrated for a high-mobility InAs nanowire device. Unlike conventional quantum point contacts (QPCs) created in two-dimensional electron gas, the QPCs represent one-dimensional constrictions formed inside quasi-one-dimensional conductor. For each QPC, local subband occupation can be controlled individually between zero and up to six degenerate modes. At large out-of-plane magnetic fields Landau quantization Zeeman splitting emerge comprehensive...
We systematically study three-terminal InSb-Al nanowire devices by using radio-frequency reflectometry. Tunneling spectroscopy measurements on both ends of the hybrid nanowires are performed while varying chemical potential, magnetic field and junction transparencies. Identifying lowest-energy state allows for construction lowest- zero-energy diagrams, which show how states evolve as a function aforementioned parameters. Importantly, comparing diagrams taken each end hybrids enables...
We describe a concrete device roadmap towards fault-tolerant quantum computing architecture based on noise-resilient, topologically protected Majorana-based qubits. Our encompasses four generations of devices: single-qubit that enables measurement-based qubit benchmarking protocol; two-qubit uses braiding to perform Clifford operations; an eight-qubit can be used show improvement operation when performed logical qubits rather than directly physical qubits; and topological array supporting...
We develop a protocol to determine the presence and extent of topological phase with Majorana zero modes in hybrid superconductor-semiconductor device. The is based on conductance measurements three-terminal device two normal leads one superconducting lead. A radio-frequency technique acts as proxy for measurement local conductance, allowing rapid, systematic scan large experimental space cause bias peaks at each end wire, so we identify promising regions by filtering this condition. To...
In superconducting quantum circuits, aluminum is one of the most widely used materials. It currently also superconductor choice for development topological qubits. However, aluminum-based devices suffer from poor magnetic field compatibility. Herein, this limitation resolved by showing that adatoms heavy elements (e.g., platinum) increase critical thin films more than a factor two. Using tunnel junctions, it shown increased resilience originates spin-orbit scattering introduced Pt. This...
We measure the charge periodicity of Coulomb blockade conductance oscillations a hybrid InSb-Al island as function gate voltage and parallel magnetic field. The changes from $2e$ to $1e$ at gate-dependent value field, ${B}^{*}$, decreasing high low limit upon increasing voltage. In region between two limits, which our numerical simulations indicate be most promising for locating Majorana zero modes, we observe correlated peak spacings heights. For positive voltages,...
We report on the conditions necessary for electrical injection of spin-polarized electrons into indium nitride nanowires synthesized from bottom up by molecular beam epitaxy. The presented results mark first unequivocal evidence spin III-V semiconductor nanowires. Utilizing a newly developed preparation scheme, we are able to surmount shadowing effects during metal deposition. Thus, avoid strong local anisotropies that arise if ferromagnetic leads wrapping around nanowire. Using combination...
High-quality CdS nanowires with uniform Sn doping were synthesized using a Sn-catalyzed chemical vapor deposition method. X-ray diffraction and transmission electron microscopy demonstrate the single crystalline wurtzite structure of CdS/Sn nanowires. Both donor acceptor levels, which originate from amphoteric nature in II-VI semiconductors, are identified low-temperature microphotoluminescence. This self-compensation effect was cross examined by gate modulation temperature-dependent...
We have modeled InAs nanowires using finite element methods considering the actual device geometry, semiconducting nature of channel and surface states, providing a comprehensive picture charge distribution gate action. The effective electrostatic width screening effects are taken into account. A pivotal aspect is that coupling to nanowire compromised by concurrent electrode surface/interface which provide vast majority carriers for undoped nanowires. In conjunction with field-effect...
We compute analytically the weak (anti)localization correction to Drude conductivity for electrons in tubular semiconductor systems of zinc blende type. include linear Rashba and Dresselhaus spin-orbit coupling (SOC) compare wires standard growth directions $\langle100\rangle$, $\langle111\rangle$, $\langle110\rangle$. The motion on quasi-two-dimensional surface is considered diffusive both directions: transversal as well along cylinder axis. It shown that SOC similarly affect spin...
Abstract Semiconducting–superconducting hybrids are vital components for the realization of high‐performance nanoscale devices. In particular, semiconducting–superconducting nanowires attract widespread interest owing to possible presence non‐abelian Majorana zero modes, which quasiparticles that hold promise topological quantum computing. However, systematic search Majoranas signatures is challenging because it requires reproducible hybrid devices and reliable fabrication methods. This work...
We demonstrate the growth and structural characteristics of InAs nanowire junctions evidencing a transformation crystalline structure. The are obtained without use catalyst particles. Morphological investigations reveal three structures having an L-, T-, X-shape. formation mechanisms these have been identified. NW large sections zinc blende crystal structure free extended defects, despite high stacking fault density in individual nanowires. This segment junction is associated with phase...
We report on a prototype device geometry where number of quantum point contacts are connected in series single quasi-ballistic InAs nanowire. At finite magnetic field the backscattering length is increased up to micron-scale and adiabatically. Hence, several input gates can control outcome ballistic logic operation. The absence explained terms selective population spatially separated edge channels. Evidence provided by regular Aharonov–Bohm-type conductance oscillations transverse fields,...
Detecting the transmission phase of a quantum dot via interferometry can reveal symmetry orbitals and details electron transport. Crucially, will enable read-out topological qubits based on one-dimensional nanowires. However, measuring in nanowire has not yet been established. Here, we exploit recent breakthroughs growth networks demonstrate interferometric nanowire-based architecture. In our two-path interferometer, define one branch use other path as reference arm. We observe Fano...
Semiconducting nanowire Josephson junctions represent an attractive platform to investigate the anomalous effect and detect topological superconductivity. However, external magnetic field generally suppresses supercurrent through hybrid significantly limits range in which phenomena can be studied. In this work, we impact of length InSb-Al on resilience against fields. We find that critical parallel considerably enhanced by reducing junction length. Particularly, 30 nm long persist up 1.3 T...
The fusion of non-Abelian anyons or topological defects is a fundamental operation in measurement-only quantum computation. In superconductors, this amounts to determination the shared fermion parity Majorana zero modes. As step towards this, we implement single-shot interferometric measurement indium arsenide-aluminum heterostructures with gate-defined nanowire. interferometer formed by tunnel-coupling proximitized nanowire dots. causes state-dependent shift these dots' capacitance up 1 fF....
With the direct measurement of quantum oscillatory magnetization $M$ a two-dimensional electron system (2DES) in an InGaAs/InP asymmetric well we discover frequency anomaly de Haas--van Alphen effect which is not consistent with existing theories on spin-orbit interaction (SOI). Strikingly, magnetoresistance same heterostructure, that is, Shubnikov--de Haas conventionally used to explore SOI, does show anomaly. This explains why our finding has been reported for almost three decades. The...
Electrical transport in epitaxially merged InAs nanowire junctions and networks is investigated. Single-crystalline zinc blende regions form at the L- T-shaped links. The impact of junction on electrical examined room temperature cryogenic temperatures. cross configuration utilized to compare properties extracted from Hall effect field-effect transistor characterizations. As a service our authors readers, this journal provides supporting information supplied by authors. Such materials are...