A5064466798- Graphene research and applications
- Quantum and electron transport phenomena
- 2D Materials and Applications
- Topological Materials and Phenomena
- Molecular Junctions and Nanostructures
- Graphene and Nanomaterials Applications
- Nanowire Synthesis and Applications
- Perovskite Materials and Applications
- Electronic and Structural Properties of Oxides
- Strong Light-Matter Interactions
- Carbon Nanotubes in Composites
- Carbon and Quantum Dots Applications
- Advanced Thermodynamics and Statistical Mechanics
- Diamond and Carbon-based Materials Research
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Quantum Information and Cryptography
- Fuel Cells and Related Materials
- Advancements in Semiconductor Devices and Circuit Design
- Advanced Memory and Neural Computing
- Semiconductor materials and devices
ETH Zurich
2019-2025
National Institute for Materials Science
2024
Fermi nesting Correlated states have been shown to emerge in bilayer and trilayer graphene with the two-dimensional layers at just right angle respect each other. Key enhanced importance of interactions are so-called moiré electronic bands that form such systems. Rickhaus et al . explored a related system two bilayers twisted The twist was set so layer coupling strong enough but weak for carrier concentration top bottom be controlled separately. Doping electrons holes, researchers created...
Crystal fields occur due to a potential difference between chemically different atomic species. In Van-der-Waals heterostructures such are naturally present perpendicular the planes. It has been realized recently that twisted graphene multilayers provide powerful playgrounds engineer electronic properties by number of layers, twist angle, applied electric biases, interactions and elastic relaxations, but crystal have not received attention they deserve. Here we show bandstructure large-angle...
Van der Waals heterostructures provide a versatile platform for tailoring electronic properties through the integration of two-dimensional materials. Among these combinations, interaction between bilayer graphene and transition metal dichalcogenides (TMDs) stands out due to its potential inducing spin-orbit coupling (SOC) in graphene. Future devices concepts require understanding precise nature SOC TMD/bilayer influence on transport phenomena. Here, we experimentally confirm presence two...
Current semiconductor qubits rely either on the spin or charge degree of freedom to encode quantum information. By contrast, in bilayer graphene valley freedom, stemming from crystal lattice symmetry, is a robust number that can therefore be harnessed for this purpose. The simplest implementation qubit would two states with opposite valleys as case single-carrier dot immersed small perpendicular magnetic field (B⊥ ≲ 100 mT). However, excited spectrum has not been resolved date relevant...
Abstract Germanium (Ge) nanowires hold great promise as building blocks for hole spin‐based quantum processors. Realizing this potential requires their direct integration onto silicon (Si) wafers. This work introduces V‐groove‐confined selective epitaxy to enable the in‐plane growth of on Si substrates. Nanowires form fully confined within V‐shaped grooves, a process driven by surface energy minimization and in agreement with Winterbottom‐like construction calculations. confinement...
The intrinsic valley degree of freedom makes bilayer graphene a unique platform for emerging types semiconducting qubits. single-carrier quantum dot ground state exhibits two-fold degeneracy where the two states have opposite spin and numbers. By breaking time-reversal symmetry this with an out-of-plane magnetic field, novel type qubit (Kramers qubit), encoded in two-dimensional spin-valley subspace, becomes accessible. Kramers is robust against known spin- valley-mixing mechanisms, as it...
Control over minivalley polarization and interlayer coupling is demonstrated in double bilayer graphene twisted with an angle of 2.37\ifmmode^\circ\else\textdegree\fi{}. This intermediate small enough for the minibands to form large such that charge carrier gases layers can be tuned independently. Using a dual-gated geometry we identify control all possible combinations via population two bilayers. An applied displacement field opens band gap either bilayers, allowing us even obtain full...
Electron optics in the solid state promises new functionality electronics through possibility of realizing micrometer-sized interferometers, lenses, collimators and beam splitters that manipulate electrons instead light. Until now, however, such has been demonstrated exclusively one-dimensional devices, as nanotubes, graphene-based devices operating with p-n junctions. In this work, we describe a novel mechanism for electron two dimensions. By studying two-dimensional Fabry-P\'{e}rot...
${\mathrm{MoS}}_{2}$ is an emergent van der Waals material that shows promising prospects in semiconductor industry and optoelectronic applications. However, its electronic properties are not yet fully understood. In particular, the nature of insulating state at low carrier density deserves further investigation, as it important for fundamental research this study we investigate a dual-gated exfoliated bilayer field-effect transistor by performing magnetotransport experiments. We observe...
The low-energy band structure of few-layer MoS2 is relevant for a large variety experiments ranging from optics to electronic transport. Its characterization remains challenging due complex multiband behavior. We investigate the conduction dual-gated three-layer by means magnetotransport experiments. total carrier density tuned voltages applied between and both top bottom gate electrodes. For asymmetrically biased gates, electrons accumulate in layer closest positively electrode. In this...
We investigate the magnetoresistance of a dual-gated bilayer <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mi>Mo</a:mi><a:msub><a:mi mathvariant="normal">S</a:mi><a:mn>2</a:mn></a:msub></a:mrow></a:math> encapsulated by hexagonal boron nitride. At low magnetic fields (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mo>|</c:mo><c:mi>B</c:mi><c:mo>|</c:mo><c:mo><</c:mo><c:mn>0.5</c:mn><c:mspace width="4pt"/><c:mi...
Van der Waals heterostructures provide a versatile platform for tailoring electronic properties through the integration of two-dimensional materials. Among these combinations, interaction between bilayer graphene and transition metal dichalcogenides (TMDs) stands out due to its potential inducing spin-orbit coupling (SOC) in graphene. Future devices concepts require understanding precise nature SOC TMD/bilayer influence on transport phenomena. Here, we experimentally confirm presence two...
We measure the entropy change of charge transitions in an electrostatically defined quantum dot bilayer graphene. Entropy provides insights into equilibrium thermodynamic properties both ground and excited states beyond transport measurements. For one-carrier regime, obtained shows that state has a two-fold degeneracy lifted by out-of-plane magnetic field. This observation is agreement with previous direct measurements confirms applicability this novel method. two-carrier extracted indicates...
We measured the spectrum of a single-carrier bilayer graphene quantum dot as function both parallel and perpendicular magnetic fields, using time-resolved charge detection technique that gives access to individual tunnel events. Thanks our unprecedented energy resolution 4$\mu~$eV, we could distinguish all four levels dot's first orbital, in particular range fields where second excited states cross ($B_\perp\lesssim 100~$mT). thereby experimentally establish, hitherto extrapolated,...
We implement circuit quantum electrodynamics (cQED) with dots in bilayer graphene, a maturing material platform that can host long-lived spin and valley states. Our device combines high-impedance (Zr ≈ 1 kΩ) superconducting microwave resonator double dot electrostatically defined graphene-based van der Waals heterostructure. Electric dipole coupling between the subsystems allows to sense electric susceptibility of from which we reconstruct its charge stability diagram. achieve sensitive fast...
We implement circuit quantum electrodynamics (cQED) with dots in bilayer graphene, a maturing material platform for semiconductor qubits that can host long-lived spin and valley states. The presented device combines high-impedance ($Z_\mathrm{r} \approx 1 \mathrm{k{\Omega}}$) superconducting microwave resonator double dot electrostatically defined graphene-based van der Waals heterostructure. Electric dipole coupling between the subsystems allows to sense electric susceptibility of from...