A5049108073- Quantum and electron transport phenomena
- Semiconductor Quantum Structures and Devices
- Physics of Superconductivity and Magnetism
- Advancements in Semiconductor Devices and Circuit Design
- Surface and Thin Film Phenomena
- Semiconductor materials and devices
- Electronic and Structural Properties of Oxides
- Magnetism in coordination complexes
- Nanowire Synthesis and Applications
- Magnetic properties of thin films
- Lanthanide and Transition Metal Complexes
- Molecular Junctions and Nanostructures
- Advanced Semiconductor Detectors and Materials
- Topological Materials and Phenomena
- Theoretical and Computational Physics
- Advanced NMR Techniques and Applications
- Semiconductor Lasers and Optical Devices
- Advanced Condensed Matter Physics
- Graphene research and applications
- Electron Spin Resonance Studies
- Magnetic and transport properties of perovskites and related materials
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Quantum Information and Cryptography
- ZnO doping and properties
Weizmann Institute of Science
2016-2025
University of Oxford
2002
City College of New York
2001-2002
University of Cambridge
2000-2002
Technion – Israel Institute of Technology
1983-1997
IBM Research - Thomas J. Watson Research Center
1988-1992
Soreq Nuclear Research Center
1978-1990
Israel Atomic Energy Commission
1978-1990
AT&T (United States)
1985
Nokia (United States)
1982
We demonstrate that the conductance through a single-electron transistor at low temperature is in quantitative agreement with predictions of equilibrium Anderson model. The Kondo effect observed when an unpaired electron localized within transistor. Tuning electron's energy toward Fermi level nearby leads produces crossover between and mixed-valence regimes
Via a novel interference experiment, which measures magnitude and phase of the transmission coefficient through quantum dot in Coulomb regime, we prove directly, for first time, that transport has coherent component. We find same at successive peaks, each representing different number electrons dot; however, as scan single peak an abrupt change \ensuremath{\pi}. The observed behavior cannot be understood particle framework.
A theoretical description of vortex dynamics in thin flat samples is derived and found to compare favorably with experimental results. In perpendicular applied magnetic field the penetration delayed significantly due presence a potential barrier geometrical origin. This novel effect results hysteretic magnetization existence an irreversibility line absence bulk pinning. Among unique characteristics are concentration center sample zero-field peak loops.
We have observed asymmetric Fano resonances in the conductance of a single-electron transistor resulting from interference between resonant and nonresonant path through system. The component shows all features typical addition to confined droplet within transistor, but origin is unclear. A feature this experimental system, compared others that show line shapes, changing voltages on various gates allows one alter two paths.
We report on optical measurements of a two-dimensional electron gas near the metal-insulator transition. observe appearance excitons and negatively charged excitons, ${X}^{\ensuremath{-}}$, at onset The fact that these appear relatively large average density shows transition is induced by localization single electrons in electrostatic potential fluctuations remote ionized donors.
We report on transport measurements in a novel system composed of two parallel 2D electron and hole gases separated by barrier which is high enough to prevent tunneling recombination while thin allow for strong interlayer Coulomb interaction. Separate electrical contacts each layer independent control both carrier densities facilitate detailed study the electron-hole Current driven one found induce opposite current other layer. The measured momentum-transfer rate factor 5 an order magnitude...
Wideband shot noise, associated with dc current flow through a quantum point contact (QPC), is measured in the microwave frequency range of 8--18 GHz. As number conducting channels QPC changes noise power oscillates. Consistent existing theories, peaks depend linearly on current. Surprisingly, however, pinch off region, where expected to behave as classical injector, we find strong suppression, possibly mediated by Coulomb interaction.
We measured the phase evolution of electrons as they traverse a quantum dot (QD) formed in two-dimensional electron gas that serves localized spin. The traversal phase, determined by embedding QD double path interferometer and measuring interference wave functions manifested conductance oscillation function weak magnetic field, evolved pi radians, range twice large theoretically predicted. As correlation weakened, gradual transition to familiar was observed. specific observed is highly...
We report on a zero magnetic field transport study of two-dimensional, variable-density, hole system in GaAs. As the density is varied we observe, for first time GaAs-based materials, crossover from an insulating behavior at low-density, to metallic-like high-density, where metallic characterized by large drop resistivity as temperature lowered. These results are agreement with recent experiments Si-based two-dimensional systems Kravchenko et al. and others. show that, region, dominated...
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.
The growth of wurtzite GaAs and InAs nanowires with diameters a few tens nanometers negligible intermixing zinc blende stacking is reported. suppression the number faults was obtained by procedure within vapor−liquid−solid growth, which exploits theoretical result that small diameter (∼10 nm) adopt purely structure are observed to thicken (via lateral growth) once axial exceeds certain length.
Incorporation of catalyst atoms during the growth process semiconductor nanowires reduces electron mean free path and degrades their electronic properties. Aberration-corrected scanning transmission microscopy (STEM) is now capable directly imaging single Au within dense matrix a GaAs crystal, by slightly tilting lattice planes with respect to incident beam. doping values in order 10(17-18) cm(3) were measured, making ballistic transport through practically inaccessible.
Scaling laws and universality play an important role in our understanding of critical phenomena the Kondo effect. We present measurements nonequilibrium transport through a single-channel quantum dot at low temperature bias. find that low-energy conductance is consistent with between bias characterized by quadratic scaling exponent, as expected for spin-1/2 show are well described universal function two parameters.
We report on a comprehensive study of spin-$\frac{1}{2}$ Kondo effect in strongly coupled quantum dot realized high-quality InAs nanowire. The nanowire is relatively symmetrically to its two leads, so the reaches unitary limit. measured conductance demonstrates scaling with temperature, Zeeman magnetic field, and out-of-equilibrium bias. suppression field much stronger than would be expected based $g$-factor extracted from splitting peak. This may related strong spin-orbit coupling InAs.
We report the observation of positively charged exciton and triplet state negatively in modulation doped GaAs quantum wells. Applying a gate voltage at high magnetic fields we find that photoluminescence line two-dimensional electron gas smoothly transforms into not neutral exciton. The Zeeman splitting this exhibits an abrupt change metal-insulator transition.