Electronic coherence in delta-Pu: a dynamical mean-field theory study.
C A Marianetti1, K Haule, G Kotliar
1Lawrence Livermore National Laboratory, Livermore, CA, USA.
Physical Review Letters
|September 4, 2008
Summary
Density functional theory and dynamical mean-field theory reveal delta-plutonium exhibits Pauli-like magnetic susceptibility due to electronic coherence, suppressing local moments. Volume expansion shifts this behavior to lower temperatures.
Area of Science:
- Solid State Physics
- Quantum Materials Science
- Computational Materials Science
Background:
- Understanding the electronic properties of plutonium (Pu) is crucial due to its unique behavior.
- Delta-phase plutonium (δ-Pu) exhibits complex electronic correlations and lacks local magnetic moments, defying simple theoretical models.
Purpose of the Study:
- To investigate the electronic and magnetic properties of δ-Pu using advanced computational methods.
- To elucidate the underlying mechanisms responsible for the absence of local moments in δ-Pu.
- To explore the influence of volume changes on the electronic behavior of δ-Pu.
Main Methods:
- Combined density functional theory (DFT) and dynamical mean-field theory (DMFT) calculations.
- Calculation of magnetic susceptibility, heat capacity, and valence band photoemission spectra.
- Analysis of the temperature and volume dependence of electronic properties.
Main Results:
- Predicted a Pauli-like magnetic susceptibility for δ-Pu near ambient temperatures, consistent with experimental observations.
- Demonstrated that electronic coherence, rather than local moments, explains the observed magnetic behavior.
- Showed that volume expansion drives a transition from incoherent to coherent electronic behavior at lower temperatures.
Conclusions:
- Electronic coherence is the key factor suppressing local moments in δ-Pu.
- Volume changes significantly impact the electronic phase of δ-Pu, enabling tuning of its properties.
- The DFT+DMFT approach provides a robust framework for understanding strongly correlated electron systems like plutonium.
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