Theoretical study of the α<->γ cerium phase transition : including strong correlations in DFT+DMFT
type: Dataset
description: The isostructural phase transition of cerium has been and remains the aim of many studies in order to test methods developed to describe strongly correlated materials.The Dynamical Mean Field Theory (DMFT) combined with density functional theory (DFT) has been successful to describe such systems.However, the computation of the ground state properties requires a very good accuracy from both DFT and DMFT sides.We use thus a strong coupling Continuous Time Quantum Monte Carlo (CT-QMC) solver, which is fast and able to reach low temperatures, in combination with a projector augmented wave (PAW) DMFT implementation to calculate internls and free energies -- and thus the entropy -- during the phase transition of cerium.Extensive calculations using this implementation allows us to carefully reassess the ground state properties and almost all thermodynamics of the α<->γ phase transition in cerium at low temperatures.In particular, stochastic noise is small enough to avoid any ambiguity on the interpretation of energy versus volume curves.On those curves, a double inflexion point is clearly observable ont the internal energy curves untill a relatively low temperature.Moreover, free energy curves highlight the importance of including the entropy contribution.The DMFT picture is put in perspective with recent DFT calculations and recent experimental investigations.Furthermore, photoemission spectra are analysed while the phase transition.Finaly, we discuss the approximations used and raise curiosity about their consideration.
identifier: NNT: 2013PA112234
issued: 2026-05-05T11:07:24.452688
language: fr
modified: 2026-05-05T11:07:24.452692
contact point: Organization
  fn: CCSD
keyword: ab-initio
keyword: cerium
keyword: correlations
keyword: dft
keyword: dmft
keyword: first-principles
keyword: infoeu-reposemanticsdoctoralthesis
keyword: kondo
keyword: localisation
keyword: localization
keyword: monte-carlo
keyword: parallelisation
keyword: parallelism
keyword: phase-transtion
keyword: phonons
keyword: physcondcm-genphysics-physicscondensed-matter-cond-matother-cond-matother
keyword: premiers-principes
keyword: thermodynamics
keyword: thermodynamique
keyword: theses
keyword: transition-de-phase
landing page: https://theses.hal.science/tel-00991785

Theoretical study of the α<->γ cerium phase transition : including strong correlations in DFT+DMFT
type: Distribution
format: HTML
issued: 2026-05-05T11:07:24.464259
modified: 2026-05-05T11:07:24.417733
access URL: https://theses.hal.science/tel-00991785

test_moissonnage_selune
type: Agent