共查询到20条相似文献,搜索用时 15 毫秒
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This Letter addresses the counterintuitive behavior of electrons injected into dense cryogenic media with negative scattering length L. Instead of strongly reduced mobility at all but the lowest densities due to the polaronic effect involving the formation of density enhancement clusters (expected in the theory with a simple gas-electron interaction successfully applied earlier to electrons in helium where L>0) which should substantially decrease the electron mobility, an opposite picture is observed: with increasing |L| (the trend taking place for inert gases with the growth of atomic number) and the gas density, the electrons remain practically free. An explanation of this behavior is provided based on consistent accounting for the nonlinearity of the electron interaction with the gaseous medium in the gas atom number density. 相似文献
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Arbouet A Voisin C Christofilos D Langot P Fatti ND Vallée F Lermé J Celep G Cottancin E Gaudry M Pellarin M Broyer M Maillard M Pileni MP Treguer M 《Physical review letters》2003,90(17):177401
Electron-lattice energy exchanges are investigated in gold and silver nanoparticles with sizes ranging from 30 to 2.2 nm embedded in different environments. Femtosecond pump-probe experiments performed in the low-perturbation regime demonstrate a strong increase of the intrinsic electron-phonon interaction for nanoparticles smaller than 10 nm due to a confinement effect. 相似文献
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The work is devoted to the investigation of the weakly bound three-body atomic clusters. The calculations on the van der Waals trimer 7Li4He2 are carried out using the differential Faddeev equations, which allows us to give accurate binding energies for both the ground and the exited state of the system. The results obtained indicate the Efimov nature of the excited state in this system. 相似文献
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B. A. Kornienkov M. A. Libman B. V. Molotilov 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(1):51-53
The effect of thermal treatment in combination with an external magnetic field and/or elastic stress on the magnetic characteristics
of amorphous metal alloys of the 2NSR type is studied. The complex behavior of the magnetization and coercivity values in
dependence on the length of annealing at temperatures below crystallization is described. It is assumed that the observed
changes in the macroscopic magnetic characteristics are associated with the formation of clusters with different degrees of
exchange interaction. 相似文献
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《Comptes Rendus Physique》2002,3(3):365-380
The recent extension of time-resolved femtosecond optical techniques to the investigation of the ultrafast electron scattering processes in metal clusters offers the unique possibility to follow their evolution from a bulk to a confined metal. The size dependent results obtained in model materials, the noble metals, are presented, focusing on the impact of the confinement on energy redistribution processes (electron–electron and electron–phonon coupling). Their application to the investigation of the acoustic vibration property of cluster and to the cluster-surrounding matrix energy transfers are also discussed. To cite this article: N. Del Fatti, F. Vallée, C. R. Physique 3 (2002) 365–380. 相似文献
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P. -G. Reinhard S. Weisgerber O. Genzken M. Brack 《Zeitschrift für Physik A Hadrons and Nuclei》1994,349(3-4):219-222
We discuss and compare the gross features of resonance excitations in nuclei and metal clusters. We point out the phenomenon of ”jellium scaling” which means that different materials for metal clusters all give similar resonance spectra and we discuss the various effects which determine the exact position of the resonance. 相似文献
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《Superlattices and Microstructures》2005,38(2):122-129
One of the remarkable properties of the II–VI diluted magnetic semiconductor (DMS) quantum dot (QD) is the giant Zeeman splitting of the carrier states under application of a magnetic field. This splitting reveals strong exchange interaction between the magnetic ion moment and electronic spins in the QD. A theoretical study of the electron spectrum and of its relaxation to the ground state via the emission of a longitudinal optical (LO) phonon, in a CdSe/ZnMnSe self-assembled quantum dot, is proposed in this work. Numerical calculations showed that the strength of this interaction increases as a function of the magnetic field to become more than 30 meV and allows some level crossings. We have also shown that the electron is more localized in this DMS QD and its relaxation to the ground state via the emission of one LO phonon is allowed. 相似文献
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Experimental data on the absorption of radiation by cold lithium, potassium, and silver clusters and on the emission of radiation
by hot niobium and tungsten clusters are analyzed within the scope of two interpretive schemes of radiative transitions in
clusters. The first scheme comprises plasmon model of light absorption by valence electrons of metal clusters. The second
scheme treats radiative transitions in metal clusters as transitions of valence electrons interacting with surrounding electrons
and atomic cores. The experimental data exhibit better agreement with the second interpretation.
Zh. éksp. Teor. Fiz. 116, 1903–1911 (December 1999) 相似文献
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We have discussed the electron states of microcrystalline structure in semiconductor by using 1-D simulation of the crystal interface potential barrier model. As the size of microcrystal granule is decreased, the widths of both the forbidden band and the band tail will be broadened gradually and exhibit the amorphous character. 相似文献
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Electron localization is studied in formamide cluster anions. The isolated
formamide molecule has a large dipole moment and its clusters can give birth
to multipole-bound anions as well as valence anions. The vertical valence
electron affinity of the isolated molecule is determined by electron
transmission spectroscopy. The anion formation process is studied as a
function of cluster size with Rydberg electron transfer spectroscopy. DFT
calculations of the neutral and negatively-charged cluster structures show
that the anion excess electron localizes on a single molecule. The adiabatic
valence electron affinity of isolated formamide is deduced from the
observation of the cluster size threshold for valence attachment. 相似文献