相关论文: Enhanced Multiple Exciton Generation in Amorphous …
Obtaining the exciton dynamics of large photosynthetic complexes by using mixed quantum mechanics/molecular mechanics (QM/MM) is computationally demanding. We propose a machine learning technique, multi-layer perceptrons, as a tool to…
Owing to their small binding energies, excitons in bulk semiconductors typically exhibit a sharp optical peak at low temperatures only. This limitation can be overcome by single-walled carbon nanotubes (SWCNTs) and other low-dimensional…
Organic molecular crystals are appealing for next-generation optoelectronic applications, most notably due to their multiexciton generation process that can increase the efficiency of photovoltaic devices. However, a general understanding…
We demonstrate storage of excitons in a single nanostructure, a self-assembled Quantum Post. After generation electron and holes forming the exciton are separated by an electric field towards opposite ends of the Quantum Post inhibiting…
Quasi-free photoproduction of eta-mesons off the neutron and off the proton has been studied using a deuterium target and bremsstrahlung photons produced by MAMI-C with incident energies up to 1.5 GeV. The eta-mesons were detected in…
Linear and nonlinear optical properties of low dimensional nanostructures have attracted a large interest in the scientific community as tools to probe the strong confinement of the electrons and for possible applications in optoelectronic…
Ultrafast and coherent generation of magnons is of great significance for high-speed antiferromagnetic spintronics. One possible route is by exciton-magnon pairwise optical excitation. To date, such exciton-magnon transitions have been…
The quantum efficiencies (QE) of photocathodes consisting of bulk Nb substrates coated with thin films of Cs2Te are reported. Using the standard recipe for Cs2Te deposition developed for Mo substrates (220 {\AA} Te thickness), a QE ~11% -…
We report on multi-photon statistics of correlated twin beams produced in a periodic poled micro-ring resonator on thin-film lithium niobate. Owing to high cavity confinement and near perfect quasi-phase matching, the photons pairs are…
We report the formation of Mn-rich regions at the interface of Co2FexMn1-xSi thin films grown on GaAs substrates by molecular beam epitaxy (MBE). Scanning transmission electron microscopy (STEM) with electron energy loss (EEL) spectrum…
We demonstrate for the first time that impact ionization (II) [the inverse of Auger recombination (AR)] occurs with very high efficiency in semiconductor nanocrystals (NCs). Interband optical excitation of PbSe NCs at low pump intensities,…
Multi-photon lasing has been realized in systems with strong nonlinear interactions between emitters and cavity modes, where single-photon processes are suppressed. Coherence between the internal states of a quantum emitter, or among…
Graphene nanoribbons (GNRs) with atomically precise width and edge structures are a promising class of nanomaterials for optoelectronics, thanks to their semiconducting nature and high mobility of charge carriers. Understanding the…
Quasi-free photoproduction of $\eta$-mesons has been measured off nucleons bound in $^3$He nuclei for incident photon energies from the threshold region up to 1.4 GeV. The experiment was performed at the tagged photon facility of the Mainz…
We study the role of the effective mass, band mixing and phonon emission on multiexciton generation in IV-VI nanocrystals. A 4-band k dot p effective mass model, which allows for an independent variation of these parameters, is adopted to…
The first measurement of coherent $\Upsilon$(1S) meson photoproduction off heavy nuclei is performed using ultraperipheral lead-lead collisions collected by the CMS experiment at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The…
Carrier Multiplication (CM) is a Coulomb-driven non-radiative recombination mechanism which leads to the generation of multiple electron-hole pairs after absorption of a single high-energy photon. Recently a new CM process, termed space…
Planar nanostructures allow near-ideal extraction of emission from a quantum emitter embedded within, thereby realizing deterministic single-photon sources. Such a source can be transformed into M single-photon sources by implementing…
Femtosecond (fs)-resolved photoemission electron micrographs of single and few-layer MoSe$_2$ track exciton dynamics in this model 2D quantum material system with joint nanometer (nm)-fs resolution. We illustrate the latter using two-photon…
We consider the charged exciton complexes of an ideal two-dimensional electron-hole system in the limit of strong magnetic fields. A series of charged multiple-exciton states is identified and variational and finite-size exact…