A5105352860- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Advancements in Semiconductor Devices and Circuit Design
- 2D Materials and Applications
- Semiconductor materials and interfaces
- Surface and Thin Film Phenomena
- Graphene research and applications
- Semiconductor materials and devices
- Magnetic properties of thin films
- Theoretical and Computational Physics
- Magnetic Properties and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetic Field Sensors Techniques
- Perovskite Materials and Applications
- Terahertz technology and applications
- Physics of Superconductivity and Magnetism
- Spectroscopy and Laser Applications
- Chalcogenide Semiconductor Thin Films
- Advanced Semiconductor Detectors and Materials
- Strong Light-Matter Interactions
- Topological Materials and Phenomena
- Semiconductor Lasers and Optical Devices
- ZnO doping and properties
- Multiferroics and related materials
- Quantum optics and atomic interactions
Centre National de la Recherche Scientifique
1993-2024
Université Grenoble Alpes
2016-2024
Laboratoire National des Champs Magnétiques Intenses
2001-2024
Université Toulouse III - Paul Sabatier
2016-2024
Wrocław University of Science and Technology
2010
Institute of Physics
2010
Ruhr University Bochum
2010
Institut National des Sciences Appliquées de Toulouse
1992-2002
Chimie du Solide et Energie
1992
University of Nottingham
1987-1990
Stacking atomic monolayers of semiconducting transition metal dichalcogenides (TMDs) has emerged as an effective way to engineer their properties. In principle, the staggered band alignment TMD heterostructures should result in formation interlayer excitons with long lifetimes and robust valley polarization. However, these features have been observed simultaneously only MoSe2/WSe2 heterostructures. Here we report on observation long-lived exciton emission a MoS2/MoSe2/MoS2 trilayer van der...
Shubnikov--de Haas and persistent-photoconductivity measurements are used to study the mobility, free-electron density (n), occupancy of DX center in heavily doped n-GaAs [Si,Sn] as a function doping level hydrostatic pressure. The results show that produces resonant donor between \ensuremath{\Gamma} L conduction-band minima at concentration comparable with level. For Si-doped samples, comparison local vibration-mode indicates can be identified ${\mathrm{Si}}_{\mathrm{Ga}}$.
Degenerate extrema in the energy dispersion of charge carriers solids, also referred to as valleys, can be regarded a binary quantum degree freedom, which potentially used implement valleytronic concepts van der Waals heterostructures based on transition metal dichalcogenides. Using magneto-photoluminescence spectroscopy, we achieve deeper insight into valley polarization and depolarization mechanisms interlayer excitons formed across MoS2/MoSe2/MoS2 heterostructure. We account for...
Magneto infrared absorption measurements have been performed in a highly doped GaAs quantum well which has lifted off and bonded to silicon substrate, order study the resonant polaron interaction. It is found that pinning of cyclotron energy occurs at an close transverse optical phonon GaAs. This unexpected result explained by model taking into account full dielectric constant well.
We report on an absolute measurement of the electronic spin polarization ν=1 integer quantum Hall state. The is extracted in vicinity (including at exactly ν=1) via resistive NMR experiments performed different magnetic fields (electron densities) and Zeeman energy configurations. At lowest fields, found to be complete a narrow region around ν=1. Increasing field density) induces significant depolarization system, which we attribute transition between ferromagnet Skyrmion glass phase...
Carrier transport in a set of AlGaN/GaN heterostructures from different sources with range carrier densities and mobilities has been investigated at low temperature high magnetic fields. The Shubnikov-de Haas oscillations have analysed to extract the quantum scattering lifetime, τq, this is compared classical τt, derived low-field mobility. relationship between these parameters observed depend systematically on mobility samples studied, indicates that higher-mobility suffer less centres...
We present an experimental study of intravalley and intervalley transport in InAs/AlSb/InAs/AlSb/InAs double barrier resonant tunneling diode at liquid helium temperatures. This work reports the first observation through InAs Γ-point quasibound state confined by AlSb X-point barriers. The incident energy electrons was tuned a transverse magnetic field (0<B<17 T). Self-consistent calculations current-voltage relation model that includes wave vector contribution to behavior...
We propose a simple phenomenological model for hydrogen atom in magnetic field which correctly reproduces the results of Makado and McGill's variational calculations $s$, $p$, $d$, $f$ states orbital quantum numbers $n\ensuremath{\le}4$. The expression energy $1s$ state reveals that it never exhibits true free carrier behavior. Even at high fields varies as ${\ensuremath{\alpha}}_{n}\ensuremath{\hbar}{\ensuremath{\omega}}_{c}/2$, where...
Monolayer transition metal dichalcogenides offer the possibility of optical control valley degree freedom. In order to asses potential these materials in applications, detailed knowledge dynamics is essential. this work, we apply low temperature time-resolved photoluminescence (PL) measurements investigate exciton relaxation and, particular, its behavior under strong excitation. At lowest excitation powers inter scattering time $\simeq 50$ ps, but shortens by more than a factor two at...
The ionization energy of DX centres in Ga(As,P) is shown to depend upon the chemical nature substitutional n-type impurity. Tellurium introduces a centre lying at about 100 meV higher than associated with other impurities (Si or Sn). A comparative study between and (Al,Ga)As alloys confirms that tellurium-related very sensitive local environment
The dependence of the electroluminescence (EL) signal from excited-state interband transitions on applied magnetic field has been investigated for two superlattice samples. Both samples show clear oscillatory behavior EL intensity as a function perpendicular field. In sample with subband splitting lowest conduction band states above longitudinal-optical (LO) phonon energy in GaAs, oscillations are due to magnetophonon effect. However, below LO-phonon series exist, which assigned different...
Positively charged excitons in a two‐dimensional hole gas symmetric and asymmetric GaAs/Ga1−xAlxAs quantum wells are studied polarization‐resolved photoluminescence experiments high magnetic fields B (up to 23 T) low temperatures (down 300 mK). The accompanied by numerical calculations of real structure. whole family trions (the singlet pair triplets) observed. Coulomb energies crossing triplet is found: hidden visible structures.
We report on the detection of sub‐THz and THz radiation by silicon FETs voltage tunable emission terahertz from InGaAs/AlInAs HEMTs with nanoscale gate lengths. The observed photo‐response is in agreement predictions plasma wave response theory. spectrum emitted signal has two peaks. lower peak interpreted as resulting Dyakonov — Shur instability gated dimensional electron fluid. measurements a magnetic field show that threshold remains close to transistor saturation increases due geometric...