Periodic Anderson model with Holstein phonons for the description of the cerium volume collapse

Abstract

Recent experiments have suggested that the electron-phonon coupling may play an important role in the γ → α volume collapse transition in Cerium. A minimal model for the description of such transition is the periodic Anderson model. In order to better understand the effect of the electron-phonon interaction on the volume collapse transition, we study the periodic Anderson model with coupling between Holstein phonons and electrons in the conduction band. We find that the electron-phonon coupling enhances the volume collapse, which is consistent with experiments in Cerium. While we start with the Kondo Volume Collapse scenario in mind, our results capture some interesting features of the Mott scenario, such as a gap in the conduction electron spectra which grows with the effective electron-phonon coupling. arXiv:1704.08684v6 [cond-mat.str-el]

Ground state properties of the periodic Anderson model with electron-phonon interactions

“…The PAM with electron-phonon interactions has been used in the theoretical description of unconventional superconductivity in heavy fermion systems [28]. For recent studies, see [12,14,42] and references therein. However, there has been no rigorous study of such models.…”

Schwinger-Dyson Equation Method to Calculate Total Energy in Periodic Anderson Model with Electron-Phonon Interactions

“…It is argued that the Cerium volume collapse should be due to the emergence of a first order phase transition. A good method to characterize this first order phase transition is to obtain pressure versus volume curves at different temperatures and see when the pressure versus volume curve develops a kink [2]. We can calculate the pressure by taking partial derivative of free energy with respect to volume, whereas free energy can be calculated once we have obtained energy as a function of temperature [3].…”