Coexistence of single particle and collective type excitation

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Kozponti Fizikai Kutato Intezet
Congresses, Nuclear excitation, Nulclear stru
The Physical Object
FormatUnknown Binding
ID Numbers
Open LibraryOL9166781M
ISBN 109633710782
ISBN 139789633710784

The photoresponse of magnetoresistance of a high-density two-dimensional electron system to microwave electromagnetic radiation is studied. The damping of the Shubnikov-de Haas oscillation by radiation with a non-monotonic dependence of this effect on the magnetic field and the radiation-induced oscillations of magnetoresistance are observed.

The damping is most pronounced Cited by: 5. Abstract. In this study, level sequences of rotational character have been observed in several nuclei in the A = 60 mass region. The importance of the deformation-driving πf 7/2 and νg 9/2 orbitals on the onset of nuclear deformation is stressed.

A measurement was performed in order to identify collective rotational structures in the relatively neutron-rich 62 Ni isotope. A study of excited states in Ni up to an excitation energy of 28 MeV and a probable spin of 57/2 was carried out with the Mg(Ca,2 alpha 3n gamma)Ni reaction at beam energies between and MeV.

Three collective bands, built upon states of single-particle character, were identified. For two of the three bands, the transition quadrupole moments were extracted, herewith Cited by: 3. ter is a sign of the breakdown of independent single-particle behavior and emergening collectivity.

Indeed the theoretical results point towards the Coexistence of single particle and collective type excitation book of single-particle and weakly collective states near the ground state of Sb. References 1) G.

Simpson et al., Phys. Rev. Lett. (). 2) H. Grawe et al., Nucl. Phys. Abstract. Based on an analysis of available theoretical and experimental data, it is shown that the collective excitation spectrum is not identical to the single-particle excitation spectrum in superfluid helium 4 He.

It is shown that collective excitations with phonon-roton spectrum are not directly related to the superfluidity by: 1. Many-body systems show incoherent, single-particle-motion, as well as coherent collective motion. Historically this phenomenon received much attention in nuclear physics where there is a wealth of data providing information on the coexistence of collective excitations, such as the Giant Dipole Resonance (GDR), and single particle excitations [1].

At the same time in the one-particle excitation spectrum a gap It is shown that the single-particle Possibility for coexistence of a phonon and one-particle spectra in ${}^4He$ at all.

() The pole of Go is at the quasi-particle energy Es. More generally, the single particle excitation energy and damping rate are given by the real and imaginary parts of the pole of G(J, ~), respectively. Thus, to find the effect of the collective states on the single particle spectrum, we must find the effect of these states on G(J, 5).

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Many-body systems show incoherent, single-particle motion, as well as coherent collective motion. Historically this phenomenon received much attention in nuclear physics where there is a wealth of data providing information on the coexistence of collective excitations, such as the giant dipole resonance (GDR), and single particle excitations [].

The main focus of this work is on the predictions made by the dielectric formalism in regard to the relationship between single-particle and collective excitation spectra in a gas of pointlike charged bosons at finite temperature T below the critical region of Bose-Einstein condensation.

Illustrative numerical results at weak coupling (r s =1) are presented within the random phase. VOL NUMBER 4 PHYSICAL REVIEW LETTERS 26JULY Single Particle and Collective Excitations in the One-Dimensional Charge Density Wave Solid KMoO3 Probed in Real Time by Femtosecond Spectroscopy J.

Demsar,1 K. Biljakovic´,2 and D. Mihailovic1 1Solid State Physics Department, “Jozef Stefan” Institute, Jam Ljubljana, Slovenia 2Institute for Physics.

est single pair excitation. F or an y ~ Q there is also a maxim um energy e-h pair whic h can b e created, namely when the hole state ~ k lies just b elo w the F ermi surface in the direction of Q, and the corresp onding electron state then lies as far as p ossible outside the F ermi sea.

This excitation has energy h 2 (k F + Q) = 2 m F. This. Many condensed-matter systems exhibit collective excitation modes involving coherent oscillations of the medium. For instance classical liquids and gases support sound waves.

On quite general grounds one expects a well-defined sound wave to exist for all wavelengths much greater than the typical particle.

Part of the NATO ASI Series book series (NSSB, volume ) Log in to check access. Buy eBook. USD Single Particle Aspects.

Front Matter. Pages Andrés J. Kreiner. Pages Collective and Quasi-Particle Degrees of Freedom in Hf (*) P. Quentin, S. Krieger, J. Libert, M. Weiss. Pages Diabatic Effects.

Nuclei with one particle outside a closed shell provide valuable information relative to the interplay between the single particle and the collective degrees of freedom. Keywords Neutron Number Band Head Single Particle Excitation Iacob V.E. et al. () Shape Coexistence in Neutron-Deficient Sb. In: Scheid W., Sandulescu A.

(eds. Based on an analysis of available theoretical and experimental data, it is shown that the collective excitation spectrum is not identical to the single-particle excitation spectrum in superfluid. Competition between single-particle and collective modes of excitation is observed in I at high spin.

Whereas rotational states, associated with a prolate pi h11/2 orbital, are yrast for spins. These considerations will drive this section throughout the comparison between electrons and photons for plasmon excitation and probing.

Studying single-particle plasmonics via a correlative study of electronic and photonic excitations has been the focus of some review papers in the past and recently. Herein, we focus exclusively on concepts. Namely, this is the interaction of a collective mode of the system with a single individual (single-particle).

In the single process of wave-particle interaction, the energy can be transferred from the wave to the particle or from the particle to the wave, provided that the phase velocity of the wave is slightly greater or slightly smaller than. 4. Summary. In this paper we have investigated the shape co-existence phenomenon in N = 28 isotones by employing the relativistic mean-field plus BCS (RMF+BCS) approach.For our study, the RMF calculations are carried out using the TMA parameter and the results of single particle spectra, binding energy, excitation energy, etc., are analyzed for the phenomenon of shape co-existence.

Description Coexistence of single particle and collective type excitation PDF

The single-particle cross section for the removal of a nucleon depends on the binding energy of the removed nucleon. Calculations using the formalism of show that for the relevant orbitals 1 f 7 / 2, 2 p 3 / 2, 1 f 5 / 2, 2 p 1 / 2, and 1 g 9 / 2, for the same excitation energy the single-particle cross sections for the removal of a neutron.

In other words, the single-particle picture of the shell model emerges as a result of collective effects of all nucleons generating the self-consistent mean field.

It implies that the single-particle potential of the nucleus is a deformable quantum object [4, 5, 18]. Recently the arguments and the preliminary estimations on coexistence of two branches of spectrum -the Bogolyubov's collective, and a new -one-particle with a gap, have been done in [7][8] [9] [   Coexistence of different shapes in a single nucleus, and shape (phase) For a self-consistent description of collective excitation spectra and electromagnetic transition rates, the framework of (relativistic) energy density functionals has to be extended to take into account collective correlations in relation to restoration of broken.

Single particle estimates (also called Weisskopf estimates) T(E1) = x (E) 3 A2/3 T(E2) = x (E) 5 A4/3 T(M1) = x (E) 3 T(M2) = x (E) 5 A2/3 Measuring level lifetimes gives us transition rates which can be interpreted as single particle (or collective) and hence give an indication of the type of motion.

These calculations associate the (1/2 −) state with the excitation of four neutrons into the orbitals, in addition to the excitation of a single proton out of the single-particle state. A rotational band is predicted on top of the calculated (1/2 −) state with a large, constant intrinsic quadrupole moment of e fm 2 [ 78 ].

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Shown in the top panel of Fig. 1 is a portion of the spectrum of γ rays in coincidence with the keV 2 2 + → 2 1 + γ ray, showing clearly the presence of a newly observed keV γ-ray decay of the keV placement is shown in the partial level scheme in Fig.

the observation of the γ-ray transitions to the 0 1, 2 + and 4 1 + levels, the spin-parity of the keV. In summary, we have presented how type II shell evolution driven by the tensor force can contribute to the appearance and stability of shape coexistence.

Due to type II shell evolution, the single-particle energies can be re-arranged with reduced spin-orbit splitting. From the analysis of the collective kinetic energy in the intrinsic system, the higher-order anharmonic terms including the coupling with two-quasi-particle non-collective states play an essential.

can be well understood as interplay between collective and single particle degrees of freedom. The collective and the nucleonic motion are strongly coupled, because the time scales of the collective and the single particle motion are the same.

The collective motion, which is of rotational type, can be treated in the framework of mean-field theory. The residual homogeneous linewidth of individual nanocrystals reaches up to 75% of the ensemble spectral width. Single nanocrystals undergo spectral diffusion which also contributes to the inhomogeneous band.

Excitation with two lasers with energies above and below the bandgap reveals coexistence of two emitting donor states within one particle.A collective quantized vibration on a substrate with a fractal structure.

Fracton (subdimensional particle) An emergent quasiparticle excitation that is immobile when in isolation. Holon (chargon) A quasi-particle resulting from electron spin-charge separation Leviton: A collective excitation of a single .The level structure shows mainly single particle character.

In 97 Mo, the ground state level sequence has been extended to ≏ MeV while the previous information had been up to MeV. A negative parity band built on keV (11/2 −) excited state has been extended to MeV. The structure seems to show a coexistence of single particle.