A5072117418- Nanowire Synthesis and Applications
- Optical Coatings and Gratings
- Topological Materials and Phenomena
- Nanofabrication and Lithography Techniques
- Surface Roughness and Optical Measurements
- Quantum and electron transport phenomena
- Advancements in Semiconductor Devices and Circuit Design
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Advanced Surface Polishing Techniques
- Semiconductor Quantum Structures and Devices
- Photonic and Optical Devices
- Physics of Superconductivity and Magnetism
- Chalcogenide Semiconductor Thin Films
- Near-Field Optical Microscopy
- Semiconductor materials and interfaces
- Additive Manufacturing and 3D Printing Technologies
- Advanced Measurement and Metrology Techniques
- Photonic Crystals and Applications
- Advanced biosensing and bioanalysis techniques
- Injection Molding Process and Properties
- Surface and Thin Film Phenomena
- Advanced Semiconductor Detectors and Materials
- Molecular Junctions and Nanostructures
- Advancements in Photolithography Techniques
Microsoft (United States)
2023-2025
University of Copenhagen
2010-2022
Danish National Metrology Institute
2014-2017
Statistics Denmark
2014-2017
Paul Scherrer Institute
2014
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.
Au free GaAs nanowires with zinc blende structure, of twin planes and remarkable aspect ratios, have been grown on (111) Si substrates by molecular beam epitaxy. Nanowires diameters down to 20 nm are obtained using a thin native oxide layer the substrates. We discuss how structural phase distribution along wire length is controlled effective V/III ratio temperature at growth interface explain obtain pure plane structure.
Nanowire (NW) crystal growth via the vapour_liquid_solid mechanism is a complex dynamic process involving interactions between many atoms of various thermodynamic states. With increasing speed over last few decades works have reported on aspects mechanisms, both experimentally and theoretically. We will here propose general continuum formalism for kinetics based parameters transition state kinetics. use together with key elements recent research to present more overall treatment III_V NW...
Scatterometry is a fast, precise and low cost way to determine the mean pitch dimensional parameters of periodic structures with lateral resolution few nanometer. It robust enough for in-line process control accurate metrology measurements. Furthermore, scatterometry non-destructive technique capable measuring buried structures, example grating covered by thick oxide layer. As non-imaging technique, mathematical modeling needed retrieve structural that describe surface. In this review, three...
We present transport spectroscopy of sub-gap states in a bottom gated InAs nanowire coupled to normal lead and superconducting aluminium lead. The device shows clearly resolved which we can track as the coupling parameters system are tuned gap is closed by means magnetic field. systematically extract using numerical renormalization group theory fits level quantum dot through phase transition electrostatically magnetically. also give an intuitive description excitations.
The perspectives offered by vertical arrays of nanowires for biosensing applications in living cells depend on the access individual to cell interior. Recent results electrical and molecular delivery suggest that direct is not always obtained. Here, we present a generic approach directly visualize membrane conformation interfaced with nanowire arrays, single resolution. method combines confocal z-stack imaging an optimized labelling strategy which was applied HEK293 2–11 μm long 3–7 spaced...
Polydimethylsiloxane (PDMS) is a widely used material for fabrication of microfluidic devices and replication micro- nanotextured surfaces. Shrinkage PDMS in the process can lead to leaking poor alignment layers. However, corrections mold master are seldom applied counteract shrinkage PDMS. Also, perform metrological measurements using replica techniques one has take into account. Thus we report study with several different mixing ratios curing temperatures. The factor, its associated...
Indium arsenide (InAs) nanowires (NWs) are a promising platform to fabricate quantum electronic devices, among others they have strong spin-orbit interaction (SOI). The controlled tuning of the SOI is desired in spin based devices. In this study we investigate possibility by electrostatic field, which generated back gate and two side gates placed on opposite sides NW. strength analyzed weak anti-localization effect. We demonstrate that can be strongly tuned factor 2 with electric field...
We report a study of the correlation between three optical methods for characterizing surface roughness: laboratory scatterometer measuring bi-directional reflection distribution function (BRDF instrument), simple commercial (rBRDF and confocal profiler. For each instrument, effective range spatial wavelengths is determined, common bandwidth used when comparing evaluated roughness parameters. The compared parameters are: root-mean-square (RMS) profile deviation (Rq), RMS slope (Rdq),...
A Cooper pair splitter consists of a central superconducting contact, S, from which electrons are injected into two parallel, spatially separated quantum dots (QDs). This geometry as well electron interactions can lead to correlated electrical currents due the spatial separation spin-singlet pairs S. We present experiments on such device with series bottom gates, allows for resolved tuning tunnel couplings between QDs and contacts QDs. Our main findings gate-induced transitions positive...
In-situ monitoring of the crystal structure formation during Ga-assisted GaAs nanowire growth on Si(111) substrates has been performed in a combined molecular beam epitaxy and x-ray characterization experiment. Under Ga rich conditions, we show that an increase V/III ratio increases rate wurtzite structure. Moreover, response time for changes structural phase to fluxes is observed be much longer than predicted scales adatom kinetics liquid diffusion. This suggests morphology interface plays...
Protein microarrays are valuable tools for protein assays. Reducing spot sizes from micro- to nano-scale facilitates miniaturization of platforms and consequently decreased material consumption, but faces inherent challenges in the reduction fluorescent signals compatibility with complex solutions. Here we show that vertical arrays nanowires (NWs) can overcome several bottlenecks using nanoarrays extraction analysis proteins. The high aspect ratio NWs results a large surface area available...
A magnetic impurity coupled to a superconductor gives rise Yu-Shiba-Rusinov (YSR) state inside the superconducting energy gap. With increasing exchange coupling excitation of this eventually crosses zero and system switches YSR groundstate with bound quasiparticles screening spin by $\hbar/2$. Here we explore InAs nanowire double quantum dots tunnel demonstrate spin-1/2 spin-1 states. Gating dot through 9 different charge states, show that honeycomb pattern zero-bias conductance peaks,...
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...
The growth of self-assisted InAs nanowires (NWs) by molecular beam epitaxy (MBE) on Si(111) is studied for different parameters and substrate preparations. thickness the oxide layer present surface observed to play a dominant role. Systematic use pre-treatment methods provides information influence NW morphology rates, which can be used optimizing conditions. We show that it possible obtain 100% vertical NWs no parasitic bulk structures between thickness. For temperature 460°C V/III ratio...
We present an optical metrology system for characterization of topography micro/nano-structures on a surface or embedded in semi-transparent material.Based the principles scatterometry, where intensity scattered light is used as 'fingerprint' to reconstruct surface, this new imaging scatterometer can easily find areas interest cm scale and measure multiple segments simultaneously.The measures structural features, such height, width, sidewall angle grating locally few µm2 with nm...
Semiconducting nanowires (NWs) are a versatile, highly tunable material platform at the heart of many new developments in nanoscale and quantum physics. Here, we demonstrate charge pumping, i.e., controlled transport individual electrons through an InAs NW dot (QD) device frequencies up to $1.3\,$GHz. The QD is induced electrostatically by series local bottom gates state art geometry. A periodic modulation single gate enough obtain dc current proportional frequency modulation. bias,...
Any device exposed to ambient conditions will be prone oxidation. This may of particular importance for semiconductor nanowires because the high surface-to-volume ratio and only little is known about consequences oxidation these systems. Here, we study properties indium arsenide which were locally oxidized using a focused laser beam. Polarization dependent micro-Raman measurements confirmed presence crystalline arsenic, transmission electron microscopy diffraction showed oxide. The surface...
High aspect ratio nanostructures have gained increasing interest as highly sensitive platforms for biosensing. Here, well-defined biofunctionalized vertical indium arsenide nanowires are used to map the interaction of light with depending on their orientation and excitation wavelength. We show how act antennas modifying distribution emitted fluorescence. This work highlights an important optical phenomenon in quantitative fluorescence studies constitutes step future using such nanostructures.
We characterize nano-textured surfaces by optical diffraction techniques using an adapted commercial light microscope with two detectors, a CCD camera and spectrometer.The acquisition analyzing time for the topological parameters height, width, sidewall angle is only few milliseconds of grating.We demonstrate that has resolution in nanometer range, also environment many vibrations, such as machine floor.Furthermore, we easy method to find area interest integrated camera.