A5033022453- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Quantum Dots Synthesis And Properties
- Molecular Junctions and Nanostructures
- Graphene research and applications
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- 2D Materials and Applications
- Physics of Superconductivity and Magnetism
- Surface and Thin Film Phenomena
- Advanced Semiconductor Detectors and Materials
- Photonic Crystals and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Nanowire Synthesis and Applications
- Semiconductor materials and devices
- Diamond and Carbon-based Materials Research
- Plasmonic and Surface Plasmon Research
- Superconducting and THz Device Technology
- Chalcogenide Semiconductor Thin Films
- Dark Matter and Cosmic Phenomena
- Near-Field Optical Microscopy
- MXene and MAX Phase Materials
- Atomic and Subatomic Physics Research
- ZnO doping and properties
- Magnetic properties of thin films
Madrid Institute for Advanced Studies
2016-2025
Universidad Nacional Autónoma de México
2019-2024
IMDEA Nanoscience
2013-2022
Lancaster University
2018
National University of San Juan
2001-2017
Universidad Autónoma de Madrid
2015-2016
Centro Nacional de Biotecnología
2016
Centro Nacional de Microelectrónica
2003-2011
Consejo Superior de Investigaciones Científicas
2003-2011
Toshiba (United Kingdom)
2010
The effect of growth conditions on the morphological properties InAs/GaAs(001) quantum dots covered by a thin (<3 nm) GaAs cap has been studied atomic force microscopy. Each dot turns into an elongated nanostructure at 540 °C upon deposition in As4 atmosphere, while structures with two humps are obtained when capping 500 °C. use As2 atmosphere instead leads to formation rings. Photoluminescence spectroscopy and polarization photoluminescence (PL) 15 K show dramatic changes due...
We report the direct measurement of persistent current carried by a single electron means magnetization experiments on self-assembled $\mathrm{InAs}/\mathrm{GaAs}$ quantum rings. measured first Aharonov-Bohm oscillation at field 14 T, in perfect agreement with our model based structural properties determined cross-sectional scanning tunneling microscopy measurements. The observed magnitude magnetic moment per is remarkably large for topology nanostructures, which are singly connected and...
The fine structure of the neutral exciton in a single self assembled InGaAs quantum dot is investigated under effect lateral electric field. Stark shifts up to 1.5 meV, an increase linewidth, and decrease photoluminescence intensity were observed due We show that field strongly affects splitting active manipulation particle wave-functions. Remarkably, can be tuned over large values through zero.
We present an atomic-scale analysis of the indium distribution self-assembled In(Ga)As quantum rings (QRs) which are formed from InAs dots by capping with a thin layer GaAs and subsequent annealing. find that size shape QRs as observed cross-sectional scanning tunneling microscopy (X-STM) deviate substantially ring-shaped islands atomic force on surface uncapped QR structures. show unambiguously X-STM images remaining dot material whereas AFM erupted material. The shows asymmetric...
We propose a novel experiment, the Canfranc Axion Detection Experiment (CADEx), to probe dark matter axions with masses in range 330-460 $\mu$eV, within W-band (80-110 GHz), an unexplored parameter space well-motivated window of Quantum ChromoDynamics (QCD) axions. The experimental design consists microwave resonant cavity haloscope high static magnetic field coupled highly sensitive detecting system based on Kinetic Inductance Detectors via optimized quasi-optics (horns and mirrors)....
Room temperature photoluminescence at 1.6μm is demonstrated from InGaAs quantum dots capped with an 8nm GaAsSb well. Results obtained various sample structures are compared, including samples GaAs. The observed redshift in attributed to a type II band alignment and beneficial modification of growth kinetics during capping due the presence Sb. structure discussed on basis transmission electron microscopy results.
Liquid phase exfoliation (LPE) from the bulk is an adequate method for mass-production of thin nanosheets transition metal dichalcogenides (TMDCs). However, making suspensions in which extraordinary properties mechanically exfoliated TMDCs are observable remains a challenge. We describe mild LPE to produce luminescent MoS2 and WS2 N-methylpyrrolidone or isopropanol/water mixtures, without need purification step. The key differences our experimental procedure compared previously reported...
Disentangling the contributions of radiative and non-radiative localized plasmonic modes from photonic density states metallic nanocavities between atomically-sharp tips flat substrates remains an experimental challenge nowadays. Electroluminescence due to tunnelling through tip-substrate gap allows discerning solely excitation modes, but this information is inherently convolved with that electronic structure system. In work we present a fully procedure eliminate electronic-structure factors...
Since its discovery, graphene has been one of the most prominent 2D materials due to unique properties and broad range possible applications. In particular, half-integer Quantum Hall Effect (HI-QHE) characterized by quantization resistivity as a function applied magnetic field, offers opportunities for advancements in quantum metrology understanding topological states this material. While role disorder stabilizing plateaus (QHPs) is widely recognized, precise interplay between width,...
<title>Abstract</title> The revision of the International System Units opens new perspectives for mise en pratique SI units, fixing numerical values fundamental constants nature. Here, we show realization an intrinsic standard resistance based on memristive devices working in air, at room temperature, directly accessible to end user. Operating nanoionic cells quantum conductance regime, report a programming strategy electrochemical polishing effects, allowing control levels multiple unit and...
Este artículo responde a la pregunta: ¿cómo se caracteriza galaxia NGC 3034 (M82) través de un análisis multirango? Desde una perspectiva astrofísica, emplea marco teórico que abarca morfología galáctica y evolución estelar. La metodología incluye obtención procesamiento imágenes propias en bandas B, V, R Hα desde el observatorio Aras los Olmos, así como integración datos catálogo multirango del espectro electromagnético, incluyendo ultravioleta, óptica, infrarroja rayos X. enfoque...
Stacked layers of In(Ga)As on GaAs(001) self-assembled quantum rings (QR) for laser application have been studied. Several samples with three stacked QR grown by molecular beam epitaxy GaAs spacers from 1.5 to 14 nm. The optical and structural properties characterized photoluminescence spectroscopy atomic force microscopy, respectively. For larger that 6 nm, the present similar single layers. A semiconductor structure separated 10 nm in active region has grown. This spacer ensures...
Stacked layers of self-assembled In(Ga)As quantum rings on GaAs grown by solid source molecular beam epitaxy are studied ex situ atomic force microscopy (AFM), low temperature photoluminescence (PL) and cross-sectional transmission electron (XTEM). The influence the strain field InAs segregation surface morphology, optical properties vertical ordering three ring is analyzed for spacers between from 1.5 to 14 nm. AFM PL results show that samples with &gt;6nm have morphology similar single...
We have carried out continuous wave and time resolved photoluminescence experiments in self-assembled In(Ga)As quantum dots rings embedded field effect structure devices. In both kinds of nanostructures, we find a noticeable increase the exciton radiative lifetime with external voltage bias that must be attributed to field-induced polarizability confined electron hole pair. The interplay between recombination electronic carrier tunneling presence stationary electric is therefore investigated...
High aspect ratio pillared topographies provide a large number of mechanical cues that cells can sense and react to. pillars have been employed effectively to promote stem cell differentiation probe cellular tractions. Yet, the full potential these for mechanobiology remains insufficiently characterized. Here, response progenitor neural dense high polymer in nano‐ microscale is investigated. Thermal nanoimprinting utilized fabricate with precision well‐defined density ratio. Studies on...
Organic covalent functionalization of graphene with long-range periodicity is highly desirable-it anticipated to provide control over its electronic, optical, or magnetic properties-and remarkably challenging. In this work we describe a method for the modification strict spatial at nanometer scale. The periodic landscape provided by single monolayer grown on Ru(0001) that presents moiré pattern due mismatch between carbon and ruthenium hexagonal lattices. contains periodically arranged areas...
Abstract Nuclear spins are candidates to encode qubits or qudits due their isolation from magnetic noise and potentially long coherence times. However, weak coupling external stimuli makes them hard integrate into circuit quantum electrodynamics architectures, the leading technology for solid-state processors. Here, we study of 173 Yb(III) nuclear spin states in an [Yb(trensal)] molecule superconducting cavities. Experiments have been performed on magnetically dilute single crystals placed...
Abstract Lack of reproducibility hampers molecular devices integration into large-scale circuits. Thus, incorporating operando characterization can facilitate the understanding multiple features producing disparities in different devices. In this work, we report realization hybrid graphene field effect transistors (m-GFETs) based on 11-(Ferrocenyl)undecanethiol (FcC 11 SH) micro self-assembled monolayers (μSAMs) and high-quality (Gr) a back-gated configuration. On one hand, Gr enables redox...
We report the observation of a Purcell enhancement in-plane spontaneous emission rates InAs self-assembled quantum dots coupled to mode unidirectional photonic crystal waveguide fabricated in GaAs(001). Three-dimensional finite-difference time-domain simulations predict existence high quality-factor modes due slow light resonances waveguide. These have been observed experimentally with microphotoluminescence and produce enhanced when resonant dot.
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.
Abstract Here we present the assembly of novel transparent all-polymer distributed feedback (DFB) lasers. Flexible and highly cellulose diacetate (CdA) was employed as substrate on which gratings with different periods were engraved by thermal nanoimprinting high fidelity. Highly luminescent conjugated polymers (CP), poly (9,9-dioctylfluorene) (PFO), poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT), a blend F8BT poly(3-hexylthiophene)-poly(9,9-dioctylfluorene-alt-benzothiadiazole)...
Photoluminescence and excitation of the photoluminescence spectroscopy has been performed in single InGaAs self-assembled quantum rings embedded a field effect structure device. To determine their electronic structure, bias-dependent optical transitions have analyzed both, for individual rings, averaged ensemble. Our results are compared with theoretical model, also reported by other authors studying similar nanostructures.