Coherent band excitations in CePd3 | Argonne National Laboratory

September 11, 2018

In a study published in Science, researchers indicated that the agreement between experiment and theory shows that they have a robust first-principles understanding of the temperature dependence of f-electron coherence.

Electronic spectral function of CePd3 calculated using DFT+DMFT. (A) At 100 K, the calculations show the presence of well-defined quasiparticle bands that cross the Fermi energy–producing small electron pockets close to the center of the Brillouin zone (Γ) and the (Embedded Image) zone boundary (R). Flat unoccupied bands near 50 meV are seen at the X point (Embedded Image) and the M point (Embedded Image). (B) At 400 K, the spectral weight close to the Fermi energy is largely incoherent.

Scientific Achievement

Inelastic neutron scattering validate the ab initio theory of the crossover from incoherent to coherent electronic excitations as a function of temperature.

Significance and Impact

This coherence crossover is fundamental to many strongly correlated electron systems and is now comprehensively understood using the latest advances in experiment and theory.

Research Details

Neutron scattering measurements of full volumes of 4D S(Q,ω) were performed on Angular-Range Chopper Spectrometer (SNS) and Merlin (ISIS).
There is excellent agreement on an absolute intensity scale between measurements and ab initio calculations.
The magnetic response is modulated by the joint density-of-states of f-electron quasiparticles, strongly enhanced by local particle-hole interactions.

DOI: 10.1126/science.aan0593

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