A5011105108- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Rare-earth and actinide compounds
- Physics of Superconductivity and Magnetism
- Photonic and Optical Devices
- Quantum Dots Synthesis And Properties
- Magnetic and transport properties of perovskites and related materials
- Semiconductor materials and devices
- Photonic Crystals and Applications
- Advanced Semiconductor Detectors and Materials
- High-pressure geophysics and materials
- Electronic and Structural Properties of Oxides
- Advanced Condensed Matter Physics
- GaN-based semiconductor devices and materials
- Semiconductor Lasers and Optical Devices
- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced Battery Technologies Research
- Nuclear Materials and Properties
- Acoustic Wave Resonator Technologies
- Mechanical and Optical Resonators
- Iron-based superconductors research
- Nanowire Synthesis and Applications
- Magnetic Properties of Alloys
- Superconducting Materials and Applications
Universidad Autónoma de Madrid
2013-2024
Centro Nacional de Microelectrónica
2011
Physikalisch-Technische Bundesanstalt
2010
Leibniz University Hannover
2010
Radboud University Nijmegen
1994-1995
University of Amsterdam
1987-1994
VSL Dutch Metrology Institute
1992
University of Groningen
1989
Rijksmuseum
1987
Utrecht University
1986-1987
The possibility of spatially resolving the optical properties atomically thin materials is especially appealing as they can be modulated at micro- and nanoscale by reducing their thickness, changing doping level or applying a mechanical deformation. Therefore, spectroscopy techniques with high spatial resolution are necessary to get deeper insight into two-dimensional materials. Here we study absorption single- few-layer molybdenum disulfide (MoS2) in spectral range from 1.24 eV 3.22 (385 nm...
Specific-heat measurements have been performed on a single-crystalline sample of the heavy-fermion compound ${\mathrm{CeRu}}_{2}$${\mathrm{Si}}_{2}$ in strong magnetic fields up to 20 T along tetragonal axis temperature interval 1.5T30 K. The linear electronic term specific heat (\ensuremath{\gamma}) passes through pronounced maximum at field ${\mathit{B}}^{\mathrm{*}}$\ensuremath{\simeq}7.8 T, where metamagneticlike transition occurs. For above ${\mathit{B}}^{\mathrm{*}}$, mass enhancement...
Abstract Luminescent defects in hexagonal boron nitride (h-BN) have recently emerged as a promising platform for non-classical light emission. On-chip solutions, however, require techniques controllable in-situ manipulation of quantum light. Here, we demonstrate the dynamic spectral and temporal tuning optical emission from h-BN via moving acousto-mechanical modulation induced by stimulated phonons. When perturbed propagating acoustic phonon, optically probed radiative are periodically...
The ternary compound UNiAl, crystallizing in the ZrNiAl-type structure, is an itinerant antiferromagnet with magnetic moments of less than 0.8${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$ per U atom and a high \ensuremath{\gamma} value 164 mJ/mol ${\mathrm{K}}^{2}$. anisotropic response electronic properties to field closely connected huge uniaxial anisotropy, observed not only magnetically ordered state, but also paramagnetic region. origin this anisotropy can be found strongly hybridization....
Long distance $(1.4\text{ }\ensuremath{\mu}\text{m})$ interaction of two different InAs/GaAs quantum dots in a photonic crystal microcavity is observed. Simultaneous coupling both to the cavity demonstrated by Purcell effect measurements. Resonant optical excitation $p$ state any dots, results an increase $s$-state emission other one. The cavity-mediated can be controlled varying intensity. These represent experimental step toward realization logic operations using distant solid-state qubits.
We report the first high-precision specific-heat measurements on heavy-fermion compound ${\mathrm{UPt}}_{3}$, over a wide temperature (1.4 KT40 K) and field range (B24.5 T), thus covering metamagnetic transition at 20 T. The data, taken single-crystalline sample, show pronounced low-temperature maximum in enhanced ${\ensuremath{\gamma}}^{\mathrm{*}}$ value T for direction hexagonal plane. also investigate presence of ${\mathit{T}}^{3}$ln(T/${\mathit{T}}^{\mathrm{*}}$) contribution to...
This work investigates the growth of B-C-N layers by chemical vapor deposition using methylamine borane (MeAB) as single-source precursor. MeAB has been synthesized and characterized, paying particular attention to analysis its thermolysis products, which are gaseous precursors for growth. Samples have grown on Cu foils transferred onto different substrates their morphological, structural, chemical, electronic optical characterizations. The results these characterizations indicate a...
Single-photon emitters (SPEs) are at the basis of many applications for quantum information management. Semiconductor-based SPEs best suited practical implementations because high design flexibility, scalability and integration potential in devices. emission from ordered arrays InGaN nano-disks embedded GaN nanowires is reported. Intense narrow optical lines dot-like recombination centers observed blue-green spectral range. Characterization by electron microscopy, cathodoluminescence...
Abstract We report on the delithiation of LiCoO 2 thin films using oxalic acid (C H O 4 ) with goal understanding structural degradation an insertion oxide associated Li chemical extraction. Using a multi-technique approach that includes synchrotron radiation X-ray diffraction, scanning electron microscopy, micro Raman spectroscopy, photoelectron spectroscopy and conductive atomic force microscopy we reveal balance between selective extraction damage. identify three different regimes,...
We study the optical emission of single semiconductor quantum dots weakly coupled to a photonic-crystal micro-cavity.The linearly polarized selected dot changes continuously its polarization angle, from nearly perpendicular cavity mode at large detuning, parallel zero and reversing sign for negative detuning.The linear rotation is qualitatively interpreted in terms detuning dependent mixing states.The present result relevant achieve continuous control photon emitters.
The optical emission of InGaN quantum dots embedded in GaN nanowires is dynamically controlled by a surface acoustic wave (SAW). energy both the exciton and biexciton lines modulated over 1.5 meV range at ~330 MHz. A small but systematic difference spectral modulation reveals linear change binding with SAW amplitude. present results are relevant for dynamic control individual single photon emitters based on nitride semiconductors.
Abstract Hexagonal boron nitride (hBN) has attracted a lot of attention in the past years, thanks to its many remarkable properties. These include presence single‐photon emitters with superior optical properties, which make it an ideal candidate for plethora photonic technologies. However, despite large number experimental results and theoretical calculations, structure defects responsible observed emission is still under debate. In this work, individual atomic‐scale hBN atomic force...
Resonance Raman excitation profiles for several radial-breathing modes in carbon nanotubes have been measured using tunable lasers. It is shown that the line shapes of are a powerful tool characterization nanotubes. In particular, follow theoretical predictions single one-dimensional singularity joint density states can be assigned to armchair tubes. These assignments do not rely on quantitative details electronic structure calculations.
Photoluminescence emission spectra of self-assembled single $\mathrm{In}\mathrm{As}∕\mathrm{Al}\mathrm{As}$ quantum dots with variable size reveal typical sharp lines below $1.8\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$, corresponding to transitions between fully confined states. Above this energy the peaks disappear due $\ensuremath{\Gamma}\text{\ensuremath{-}}X$ scattering conduction electrons. Excitation biexciton line in show marked maxima at optical-phonon frequency dot and its first...
The exciton and biexciton emissions of a series single quantum dots InAs in an AlAs matrix have been studied. These consist linear cross polarized doublets showing large values both the binding energy fine-structure splitting. At increasing emission energy, corresponding to decreasing dot size, 9meV decreases down zero, reflecting possible crossover antibinding regime. Simultaneously splitting diminishes from value 0.3meV at same suggesting common origin for two effects.
The realization of reliable single photon emitters operating at high temperature and located predetermined positions still presents a major challenge for the development solid-state systems quantum light applications. We demonstrate single-photon emission from two-dimensional ordered arrays GaN nanowires containing InGaN nanodisks. structures were fabricated by molecular beam epitaxy on (0001) GaN-on-sapphire templates patterned with nanohole masks prepared colloidal lithography....
GPa-resistant conformal LiCoO2 cathodes grown by physical vapor deposition (PVD), with negative chemical expansion coefficients, are promising systems for mechanically stabilizing cathode/solid electrolyte interfaces in solid-state lithium-ion batteries. However, exploiting its potential preliminarily requires that we able to control the reversibility of Li stoichiometry under PVD conditions, which represents a major challenge since metal is lightweight, volatile and has high diffusivity. By...
Photon correlation measurements on single InAs/GaAs quantum rings embedded in a photonic crystal lattice demonstrate single-photon emission with g(2)(0) values of 0.4 and photon antibunching between the exciton biexciton emissions. The measured times excitons are longer than that biexcitons, resulting time asymmetry exciton-biexciton cross-correlation. Phonon sidebands due to piezoelectric coupling acoustic phonons broaden lines shift them lower energies at low excitation intensity.
We present band-structure calculations of ${\mathrm{SnTaS}}_{2}$, an intercalation compound in which the Sn atoms have a very uncommon linear coordination by two S and unusual formal valency ${\mathrm{Sn}}^{1+}$. The 5${p}_{x}$ 5${p}_{y}$ states show strong metal-metal bonding intercalant planes Fermi level is crossed wide band composed these 5${p}_{x}$${p}_{y}$ states. Angle-resolved photoelectron spectra are agreement with calculated structure. ${\mathrm{SnTaS}}_{2}$ metallic as reflected...
The dependence of the associative ionization process Na 3 $^{2}P_{3/2}$+Na $^{2}P_{3/2}$\ensuremath{\rightarrow}${\mathrm{Na}}_{2}$${\mathrm{}}^{+}$+${e}^{\mathrm{\ensuremath{-}}}$ on polarization laser light used for excitation was independently investigated in Utrecht and Berlin. purpose this paper is to clarify discrepancies between earlier experimental results Kircz, Morgenstern, Nienhuis, one hand, Rothe, Theyunni, Reck, Tung other hand. new confirm general data also indicate a...
We report on experimental studies of the effects induced by surface acoustic waves optical emission dynamics GaN/InGaN nanowire quantum dots.We employ stroboscopic excitation with either time-integrated or time-resolved photoluminescence detection.In absence wave, spectra reveal signatures originated from recombination neutral exciton and biexciton confined in probed dot.When is perturbed propagating embedded dot periodically strained its excitonic transitions are modulated...