相关论文: Luminescence evidence for bulk and surface exciton…
Luminescence of surface and free bulk excitons is detected in xenon for the first time for substrate-free rare-gas clusters. Xenon clusters were produced by the method of gas condensation in a supersonic jet emitted into vacuum. Optical…
The paper presents the results of the experimental study of polarization bremsstrahlung profile halfwidth performed on free xenon clusters with various atom numbers. We used 0.7- and 0.3-keV electrons to excite mainly the core and the…
For the first time in binary mixtures of solid rare gases exciton-impurity luminescence is observed from a xenon-argon system containing argon as impurity. An exciton-impurity emission band is registered for binary clusters with the…
We propose a new approach to analysis of cathodoluminescence spectra of substrate-free nanoclusters of argon produced in a supersonic jet expanding into a vacuum. It is employed to analyze intensities of the luminescence bands of neutral…
Excitons are the neutral quasiparticles that form when Coulomb interactions create bound states between electrons and holes. Due to their bosonic nature, excitons are expected to condense and exhibit superfluidity at sufficiently low…
The paper proposes a new approach to studying cathodoluminescence spectra of substrate-free rare-gas clusters produced in supersonic jets exhausting into a vacuum. The approach, which takes into account the fraction of the clustered…
Cathodoluminescence (CL) experiments at low temperature have been undertaken on various bulk and exfoliated hexagonal boron nitride (hBN) samples. Different bulk crystals grown from different synthesis methods have been studied. All of them…
An electron diffraction diagnostics of substrate-free clusters formed in N2-Kr binary jets expanding through a supersonic nozzle into vacuum was carried out. Gas mixtures contained 0.5, 1, and 6 mol.% krypton, the measured average sizes of…
Energy spectra and angular distributions have been measured of electrons that are emitted upon disassembly of $Xe_{150000}$ following irradiation by intense (10$^{15}-10^{16}$ W cm$^{-2}$) laser pulses whose durations are varied over the…
Electrons and holes can spontaneously form excitons and condense in a semimetal or semiconductor, as predicted decades ago. This type of Bose condensation can happen at much higher temperatures in comparison with dilute atomic gases.…
Kinetic Boltzmann equations are used to model the ionization and expansion dynamics of xenon clusters irradiated with short intense VUV pulses. This unified model includes predominant interactions that contribute to the cluster dynamics…
We present a novel experimental protocol using Cathodoluminescence measurements as a function of the electron incident energy to study both exciton diffusion in a directional way and surface exciton recombination. Our approach overcomes the…
The absorption and emission spectra of silicon nanocrystals up to 1 nm diameter including geometry optimization and the many-body effects induced by the creation of an electron-hole pair have been calculated within a first-principles…
We present results on the spectroscopic analysis of XMM-Newton EPIC data of the central 0.5/h_50 Mpc regions of the clusters of galaxies Coma, A1795 and A3112. The temperature of the hot intracluster gas as determined by modeling the 2 - 7…
We investigate a sample of 14 clusters of galaxies observed with XMM-Newton in a search for soft X-ray excess emission. In five of these clusters a significant soft excess is evident. This soft X-ray excess is compared with the thermal…
Rich populations of clusters have been observed after femtosecond laser ablation of bulk silicon in vacuum. Size and velocity distributions of the clusters as well as their charge states have been analyzed by reflectron time-of-flight mass…
Bubble formation in liquid xenon underneath a Thick Gaseous Electron Multiplier (THGEM) electrode immersed in liquid xenon was observed with a CCD camera. With voltage across the THGEM, the appearance of bubbles was correlated with that of…
XMM-Newton observations of seven QSOs are presented and the EPIC spectra analysed. Five of the AGN show evidence for Fe K-alpha emission, with three being slightly better fitted by lines of finite width; at the 99 per cent level they are…
About a year ago, two independent experiments [1,2], imaging indirect exciton luminescence from doped double quantum wells under applied bias and optical excitation, reported a very intriguing observation: under certain experimental…
The determination of the fractional electron abundance, Xe, in protostellar cores relies on observations of molecules, such as DCO+, H13CO+ and CO, and on chemical models to interpret their abundance. Studies of protostellar cores have…