scholarly journals Environment of Er Doped in a-Si:H and Its Relation with Photoluminescence Spectra

2006 ◽  
Vol 910 ◽  
Author(s):  
Minoru Kumeda ◽  
Yoshitaka Sekizawa ◽  
Akiharu Morimoto ◽  
Tatsuo Shimizu

AbstractThe crystal-field potential at the Er3+ ion surrounded by six oxygen ions is expanded in terms of polynomials. After converting it into equivalent angular momentum operators, the Stark-splitting of the 4I15/2 ground state of the Er3+ ion is calculated. Influence of the change in the environment of the Er3+ ion on the shift of the energy levels is investigated and compared with the observed Er photoluminescence spectrum in a-Si:H. The scattering of the calculated energy levels by the structural fluctuation around the Er3+ ion is also compared with the linewidth of the component photoluminescence lines.

2003 ◽  
Vol 770 ◽  
Author(s):  
H. Przybylinska ◽  
N. Q. Vinh ◽  
B.A. Andreev ◽  
Z. F. Krasil'nik ◽  
T. Gregorkiewicz

AbstractA successful observation and analysis of the Zeeman effect on the near 1.54 μm photoluminescence spectrum in Er-doped crystalline MBE-grown silicon are reported. A clearly resolved splitting of 5 major spectral components was observed in magnetic fields up to 5.5 T. Based on the analysis of the data the symmetry of the dominant optically active center was conclusively established as orthorhombic I (C2v), with g‼≈18.4 and g⊥≈0 in the ground state. The fact that g⊥≈0 explains why EPR detection of Er-related optically active centers in silicon may be difficult. Preferential generation of a single type of an optically active Er-related center in MBE growth confirmed in this study is essential for photonic applications of Si:Er.


1995 ◽  
Vol 09 (02) ◽  
pp. 123-133 ◽  
Author(s):  
M. E. Portnoi ◽  
E. I. Rashba

A theory of anyon excitons consisting of a valence hole and three quasielectrons with electric charges –e/3 is presented. A full symmetry classification of the k = 0 states is given, where k is the exciton momentum. The energy levels of these states are expressed by quadratures of confluent hypergeometric functions. It is shown that the angular momentum L of the exciton ground state depends on the distance between the electron and hole confinement planes and takes the values L = 3n, where n is an integer. With increasing k the electron density shows a spectacular splitting on bundles. At first a single anyon splits off of the two-anyon core, and finally all anyons become separated.


1971 ◽  
Vol 70 (3) ◽  
pp. 485-496 ◽  
Author(s):  
J. A. de Wet

Representations of the four-dimensional unitary group U4 were considered long ago by Wigner(1)as a model for nuclear isobaric multiplets. However, the Hamiltonian did not include the components of isospin which together with the spin coordinates are known to label the nuclear states. In this paper we shall find representations characterized by the eigenvalues of angular momentum J, isospin T and parity π, and will find mass relations which give good agreement with the experimental energy levels of Li6 and Be8 labelled by the same quantum numbers. The representations found by Wigner give good results for the ground state energies, or masses, of all the nuclei up to a mass number of A = 110(2), and we shall derive Wigner's representations as a special case. In fact, unless these are satisfied it is impossible for particle-like representations of U4 to exist!


2005 ◽  
Vol 862 ◽  
Author(s):  
Minoru Kumeda ◽  
Mitsuo Takahashi ◽  
Akiharu Morimoto ◽  
Tatsuo Shimizu

AbstractThe photoluminescence spectra due to Er ions doped in a-Si:H were decomposed into several lines. The 19-K spectrum was reproduced by adding four Gaussian lines whose linewidths were increased with decreasing the photon energy. Since only the lowest energy level of 4I13/2 contributes to the radiative transition at this low temperature, the energy levels in 4I15/2 split by the Stark effect can be determined. These splittings are not largely different from those for Er in aluminosilicate glass. This implies that the all nearest neighbors of Er are oxygens which have been introduced unintentionally in the sample during preparation. The change in the photoluminescence intensity by annealing is discussed in relation with the spectral change and the results of ESR measurements.


2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Gerard ’t Hooft

AbstractFast moving classical variables can generate quantum mechanical behavior. We demonstrate how this can happen in a model. The key point is that in classically (ontologically) evolving systems one can still define a conserved quantum energy. For the fast variables, the energy levels are far separated, such that one may assume these variables to stay in their ground state. This forces them to be entangled, so that, consequently, the slow variables are entangled as well. The fast variables could be the vacuum fluctuations caused by unknown super heavy particles. The emerging quantum effects in the light particles are expressed by a Hamiltonian that can have almost any form. The entire system is ontological, and yet allows one to generate interference effects in computer models. This seemed to lead to an inexplicable paradox, which is now resolved: exactly what happens in our models if we run a quantum interference experiment in a classical computer is explained. The restriction that very fast variables stay predominantly in their ground state appears to be due to smearing of the physical states in the time direction, preventing their direct detection. Discussions are added of the emergence of quantum mechanics, and the ontology of an EPR/Bell Gedanken experiment.


2005 ◽  
Vol 19 (30) ◽  
pp. 1793-1802 ◽  
Author(s):  
M. MODARRES

We investigate the possible angular momentum, l, dependence of the ground state energy of normal liquid 3 He . The method of lowest order constrained variational (LOCV) which includes the three-body cluster energy and normalization constraint (LOCVE) is used with angular momentum dependent two-body correlation functions. A functional minimization is performed with respect to each l-channel correlation function. It is shown that this dependence increases the binding energy of liquid 3 He by 8% with respect to calculations without angular momentum dependent correlation functions. The l=0 state has completely different behavior with respect to other l-channels. It is also found that the main contribution from potential energy comes from the l=1 state (p-waves) and the effect of l≥11 is less than about 0.1%. The effective interactions and two-body correlations in different channels are being discussed. Finally we conclude that this l-dependence can be verified experimentally by looking into the magnetization properties of liquid helium 3 and interatomic potentials.


2011 ◽  
Vol 20 (02) ◽  
pp. 474-481 ◽  
Author(s):  
A.B. HAYES ◽  
D. CLINE ◽  
C. Y. WU ◽  
A.M. HURST ◽  
M.P. CARPENTER ◽  
...  

A 985 MeV 178 Hf beam was Coulomb excited by a 208 Pb target at the ATLAS accelerator of Argonne National Laboratory. Gammasphere and the CHICO particle detector recorded particle-γ coincidence data. The aim was to populate and determine the mechanism of previously observed Coulomb excitation of the Kπ = 6+ (t1/2 = 77 ns ), 8- (4 s ) and 16+ (31 y ) isomer bands. New rotational bands were identified including an aligned band which appears to mix with the ground-state band (GSB) and the γ-vibrational band above ~ 12 ħ of angular momentum. Newly observed γ-decay transitions into the three isomer bands may elucidate the K-mixing which allows Coulomb excitation of these isomer bands, but direct decays from the GSB into the 16+ isomer band have not yet been confirmed.


1975 ◽  
Vol 56 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Frank C. De Lucia ◽  
Paul Helminger

2018 ◽  
Vol 6 (41) ◽  
pp. 11096-11103 ◽  
Author(s):  
Ho Jin Ma ◽  
Wook Ki Jung ◽  
Youngtae Park ◽  
Do Kyung Kim

Photoluminescence spectrum and energy levels of an Er:Y2O3–MgO nanocomposite.


2016 ◽  
Vol 94 (8) ◽  
pp. 705-711
Author(s):  
Wessameldin S. Abdelaziz

Energy levels of 249 excited levels in nickel-like erbium are calculated using the 3s23p63d10 as a ground state and the single electron excited states from n = 3 to n = 4, 5 orbitals, calculations have been performed using FAC code (Gu. Astrophys. J. 582, 1241 (2003). doi:10.1086/344745 ). The populations are calculated over electron densities from 1020 to 1023 cm−3 and electron temperatures 1/2, 3/4 of the ionization potential of Ni-like Er. The gain coefficients of the transitions are calculated.


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