scholarly journals Phonon softening and double-well potential formation due to electron–phonon interaction in heavy-fermion systems

2005 ◽  
Vol 426-431 ◽  
pp. 330-334 ◽  
Author(s):  
Keisuke Mitsumoto ◽  
Yoshiaki Ōno
1990 ◽  
Vol 163 (1-3) ◽  
pp. 667-669
Author(s):  
J. Keller ◽  
R. Bulla ◽  
Th. Höhn ◽  
K.W. Becker

1990 ◽  
Vol 41 (4) ◽  
pp. 1878-1888 ◽  
Author(s):  
J. Keller ◽  
R. Bulla ◽  
Th. Höhn ◽  
K. W. Becker

2002 ◽  
Vol 16 (24) ◽  
pp. 3595-3613 ◽  
Author(s):  
P. NAYAK ◽  
B. OJHA ◽  
S. MOHANTY ◽  
S. N. BEHERA

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.


2017 ◽  
Vol 31 (12) ◽  
pp. 1750090
Author(s):  
Jitendra Sahoo ◽  
Namita Shadangi ◽  
Pratibindhya Nayak

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.


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