Wurtzite single crystal GaN nanocolumns were grown by plasma-assisted molecular beam epitaxy on bare Si(001) substrates. Nanocolumns with diameters in the range of 20–40nm have no traces extended defects and they grow aligned along [0001] direction. Photoluminescence measurements evidence a very high quality terms intense narrow excitonic emissions. Raman scattering data show that are strain-free. These results open way to an efficient integration optoelectronic devices complementary metal...

Abstract Taking advantage of the flexibility apatite structure, nano- and micro-particles hydroxyapatite (HAp) were doped with different combinations rare earth ions (RE 3+ = Gd, Eu, Yb, Tm) to achieve a synergy among their magnetic optical properties enable application in preventive medicine, particularly diagnostics based on multimodal imaging. All powders synthesized through hydrothermal processing at T ≤ 200 °C. An X-ray powder diffraction analysis showed that all crystallized P 6 3 / m...

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 oscillating piezoelectric field of a surface acoustic wave (SAW) is employed to transport photoexcited carriers, as well spatially control exciton recombination in GaAs-based nanowires (NWs) on subns time scale. experiments are carried out core–shell NWs transferred SAW delay line LiNbO3 crystal. Carriers generated the NW by focused laser spot acoustically second location, leading remote emission light pulses synchronized with phase. dynamics carrier transport, investigated using and...

Excitons, quasiparticles consisting of electron-hole pairs bound by the Coulomb interaction, are a potential medium for processing photonic information in solid state. Information via excitons requires efficient techniques transport and manipulation these uncharged particles. We have carried out detailed investigation GaAs quantum wells surface acoustic waves. Based on results, we introduce here concept interconnection multiple remote exciton systems based long-range dipolar network...

A pencil-like morphology of homoepitaxially grown GaN nanowires is exploited for the fabrication thin conformal intrawire InGaN nanoshells which host quantum dots in nonpolar, semipolar and polar crystal regions. All three dot types exhibit single photon emission with narrow line widths high degrees linear optical polarization. The region strongly affects both wavelength lifetime, reaching subnanosecond time scales non- dots. Localization sites potential landscape, most likely induced by...

Raman measurements in high quality InN nanocolumns display a coupled LO phonon-plasmon mode together with uncoupled phonons. The is attributed to the spontaneous accumulation of electrons on lateral surfaces nanocolumns. For increasing growth temperature, electron density decreases as rate increases. present results indicate that layers do not only form polar but also occur nonpolar ones. According recent calculations, we attribute surface temperature dependent In-rich reconstruction...

We report on the modulation of indirect excitons (IXs) as well their transport by moving periodic potentials produced surface acoustic waves (SAWs). The potential induced SAW strain modifies both band gap and electrostatic field in quantum wells confining IXs, leading to changes energy. In addition, this captures transports IXs over several hundreds μm. While IX packets keep a great extent spatial shape during potential, effective velocity is lower than group increases with amplitude. This...

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 This work reports on the morphology and optical properties of wurtzite InN layers grown by plasma assisted molecular beam epitaxy (PA‐MBE) Si(111) substrates. The layer can be controlled effective indium to nitrogen flux ratio, from N‐rich conditions that lead nanorods, stoichiometric leading compact layers. nanorods deliver a much higher intensity photoluminescence emission than layers, with full width at half maximum down 34 meV, indicative high crystal quality. Raman X‐ray...

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...

The effects of the composition and strain in InGaN∕GaN multi-quantum wells on their phonon frequencies have been determined using resonant Raman scattering a wide energy range. In pseudomorphic quantum strong compensation both occurs, resulting InGaN A1LO frequency being almost independent concentration. relaxed is clearly below GaN value depends excitation energy, as reported thick films. This variation, together with resonance profile, gives direct estimate concentration its fluctuations.

Time-resolved Kerr reflectometry (TRKR) is used to investigate the long-range transport of spins by surface acoustic waves in undoped GaAs (110) quantum wells. TRKR measurements under an applied magnetic field demonstrate coherent precession optically generated electron spin during over several micrometers and yield information about relaxation processes for moving spins.

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....

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...

We employ surface acoustic waves (SAWs) to control the transfer of photo-generated carriers between interconnected quantum wells and wires (QWRs) grown on pre-patterned (311)A GaAs substrates. Optical studies, carried out under remote excitation a single QWR, have shown sharp photoluminescence lines antibunched photons with tunable emission energy. These features are attributed recombination acoustically transported in potential inhomogeneities within wire. The origin photon antibunching is...

We demonstrate an information transfer mechanism between two dissimilar remote InAs/GaAs quantum dots weakly coupled to a common photonic crystal microcavity. Bichromatic excitation in the $s$ state of one leads formation dressed states due coherent coupling laser field, resonance with dot. Information on resulting structure is read out through photoluminescence spectrum other dot, as well cavity mode. The effect also observed upon exchange and detection dots. This dot intertalk interpreted...

The localized vibrational modes associated with substitutional aluminium and nitrogen atoms in ${\mathrm{Al}}_{y}{\mathrm{Ga}}_{1\ensuremath{-}y}{\mathrm{N}}_{x}{\mathrm{As}}_{1\ensuremath{-}x}$ have been studied within first-principles density functional theory using a supercell approach. Localized related to $\mathrm{N}\text{\ensuremath{-}}{\mathrm{Al}}_{m}{\mathrm{Ga}}_{4\ensuremath{-}m}$ $(1\ensuremath{\leqslant}m\ensuremath{\leqslant}4)$ complexes identified, which reveal the formation...

We report on experimental study into the effects of surface acoustic waves optical emission dot-in-a-nanowire heterostructures in III-V material systems. Under direct excitation, excitonic energy levels III-nitride oscillate at frequency, producing a characteristic splitting lines time-integrated photoluminescence spectra. This acoustically induced periodic tuning transition energies is combined with spectral detection filtering and employed as tool to regulate temporal output anti-bunched...

Abstract A review of inelastic light scattering measurements on group III‐nitride nanocolumns grown by molecular beam epitaxy is presented. The are hexagonal, high quality single crystals with diameters in the range 20 to 100 nm, no traces extended defects. GaN bare Si substrates both (111) and (100) orientation display narrow phonon peaks, indicating absence strain inhomogeneities. This opens possibility efficient integration as optoelectronic devices complementary metal oxide semiconductor...