Effect of magnon–LA phonon interaction on LA phonon excitation at finite temperature

2008 ◽  
Vol 245 (4) ◽  
pp. 673-677 ◽  
Author(s):  
Tai-Min Cheng ◽  
Lin Li ◽  
Long-hai Shen
Keyword(s):  
Finite Temperature ◽  
Phonon Interaction ◽  
Phonon Excitation

ELECTRON-PHONON INTERACTION AND PHONON RESPONSE IN HEAVY FERMION SYSTEMS

2002 ◽  
Vol 16 (24) ◽  
pp. 3595-3613 ◽  
Author(s):  
P. NAYAK ◽  
B. OJHA ◽  
S. MOHANTY ◽  
S. N. BEHERA
Keyword(s):  
Heavy Fermion ◽  
Spectral Density Function ◽  
Response Property ◽  
Model Parameters ◽  
Phonon Interaction ◽  
Long Wavelength ◽  
Electron Phonon Interaction ◽  
Fermion Systems ◽  
Electron Phonon Coupling ◽  
Phonon Excitation

The phonon response property of the Heavy Fermion (HF) systems are investigated within the Periodic Anderson Model (PAM) to explain the observed phonon anomalies. To understand the microscopic origin of these anomalies, two different mechanisms of electron-phonon interaction, namely, the usual interaction between the phonons and the electrons in the f-bands as well as the interaction due to the hybridization term of PAM, are considered. The influence of coulomb correlation U on the phonon excitation spectrum and the spectral density function are studied for various model parameters, namely, the position of the f-level E0, the ratio r of the electron-phonon coupling strengths f1(q) and f2(q), and the effective coupling strength g. The numerical evaluations of these phonon response functions are carried out for small temperatures in the long wavelength limit, while retaining terms which are linear in correlation. The observed behavior agrees well with the general features obtained in experiment.

scholarly journals THE TFD TREATMENT OF THE QUASIPARTICLE-PHONON INTERACTION AT FINITE TEMPERATURE

1994 ◽  
Vol 09 (19) ◽  
pp. 1735-1743 ◽  
Author(s):  
D.S. KOSOV ◽  
A.I. VDOVIN
Keyword(s):  
Finite Temperature ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Elementary Excitation ◽  
Nuclear Model ◽  
Phase Approximation ◽  
Thermal Phonon ◽  
Phonon Interaction ◽  
Coupling Matrix ◽  
Hot Nuclei

The coupling of elementary excitation modes in hot nuclei is studied. For this aim the quasiparticle-phonon nuclear model (QPM) is extended to a finite temperature by using the formalism of the thermofield dynamics. First the energies and structures of one-phonon states are calculated in the thermal random phase approximation and then the thermal QPM Hamiltonian HQPM is expressed in terms of thermal quasiparticles and thermal RPA-phonons. The equation for the energies taking into account mixing of one-and two-thermal phonon states is derived. The expression of the coupling matrix element between thermal phonons is given.

Phonon response of some heavy Fermion systems in dynamic limit

2017 ◽  
Vol 31 (12) ◽  
pp. 1750090
Author(s):  
Jitendra Sahoo ◽  
Namita Shadangi ◽  
Pratibindhya Nayak
Keyword(s):  
Heavy Fermion ◽  
Periodic Anderson Model ◽  
Temperature Dependent ◽  
Effective Coupling ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Fermion Systems ◽  
Phonon Excitation ◽  
Double Time ◽  
Strength Formula

The phonon excitation spectrum of some Heavy Fermion (HF) systems in the presence of electron–phonon interaction is studied in the dynamic limit ([Formula: see text]). The renormalized excitation phonon frequencies ([Formula: see text]) are evaluated through Periodic Anderson Model (PAM) in the presence of electron–phonon interaction using Zubarev-type double time temperature-dependent Green function. The calculated renormalized phonon energy is analyzed through the plots of ([Formula: see text]) against temperature for different system parameters like effective coupling strength ‘[Formula: see text]’ and the position of [Formula: see text]-level ‘[Formula: see text]’. The observed behavior is analyzed and found to agree with the general features of HF systems found in experiments. Further, it is observed that in finite but small [Formula: see text]-values the propagating phonons harden and change to localized peaks.

scholarly journals Contribution of the Multiplicity Fluctuation in the Temperature Dependence of Phonon Spectra of Rare-Earth Cobaltites

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4316
Author(s):  
Yuri S. Orlov ◽  
Alexey E. Sokolov ◽  
Vyacheslav A. Dudnikov ◽  
Karina V. Shulga ◽  
Mikhail N. Volochaev ◽  
...  
Keyword(s):  
Rare Earth ◽  
Temperature Dependence ◽  
Ground State ◽  
Finite Temperature ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Mode Softening ◽  
Phonon Spectra ◽  
Multiplicity Fluctuation ◽  
Standard Lattice

We have studied, both experimentally and theoretically, the unusual temperature dependence of the phonon spectra in NdCoO3, SmCoO3 and GdCoO3, where the Co3+ ion is in the low-spin (LS) ground state, and at the finite temperature, the high-spin (HS) term has a nonzero concentration nHS due to multiplicity fluctuations. We measured the absorption spectra in polycrystalline and nanostructured samples in the temperature range 3–550 K and found a quite strong breathing mode softening that cannot be explained by standard lattice anharmonicity. We showed that the anharmonicity in the electron–phonon interaction is responsible for this red shift proportional to the nHS concentration.

RESONANT RAMAN SCATTERING AND EXCITON-PHONON INTERACTION IN CdTe / (Cd,Mn)Te QUANTUM WELLS

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-345-C5-348
Author(s):  
S.-K. CHANG ◽  
H. NAKATA ◽  
A. V. NURMIKKO ◽  
L. A. KOLODZIEJSKI ◽  
R. L. GUNSHOR
Keyword(s):  
Raman Scattering ◽  
Quantum Wells ◽  
Phonon Interaction ◽  
Resonant Raman ◽  
Resonant Raman Scattering

Annihilation of excitons and exciton-phonon interaction

1971 ◽  
Vol 103 (3) ◽  
pp. 431 ◽  
Author(s):  
E.F. Gross ◽  
S.A. Permogorov ◽  
B.S. Razbirin
Keyword(s):  
Phonon Interaction
Sign in / Sign up

Export Citation Format

Share Document