scholarly journals Exchange parameters of strongly correlated materials: Extraction from spin-polarized density functional theory plus dynamical mean-field theory

2015 ◽  
Vol 91 (12) ◽  
Author(s):  
Y. O. Kvashnin ◽  
O. Grånäs ◽  
I. Di Marco ◽  
M. I. Katsnelson ◽  
A. I. Lichtenstein ◽  
...  
Keyword(s):  
Field Theory ◽  
Density Functional ◽  
Mean Field Theory ◽  
Mean Field ◽  
Dynamical Mean Field Theory ◽  
Strongly Correlated ◽  
Functional Theory ◽  
Strongly Correlated Materials ◽  
Spin Polarized ◽  
Exchange Parameters

Nature of Non-magnetic Strongly-Correlated State in Plutonium

2006 ◽  
Vol 986 ◽  
Author(s):  
Leniod Purovskii ◽  
Alexander Shick ◽  
Ladislav Havela ◽  
Mikhail Katsnelson ◽  
Alexander Lichtenstein
Keyword(s):  
Field Theory ◽  
Density Functional ◽  
Local Density ◽  
Mean Field Theory ◽  
Mean Field ◽  
Dynamical Mean Field Theory ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Strongly Correlated ◽  
Starting Point

AbstractLocal density approximation for the electronic structure calculations has been highly successful for non-correlated systems. The LDA scheme quite often failed for strongly correlated materials containing transition metals and rare-earth elements with complicated charge, spin and orbital ordering. Dynamical mean field theory in combination with the first-principle scheme (LDA+DMFT) can be a starting point to go beyond static density functional approximation and include effects of charge, spin and orbital fluctuations. Ab-initio relativistic dynamical mean-field theory is applied to resolve the long-standing controversy between theory and experiment in the “simple” face-centered cubic phase of plutonium called δ-Pu. In agreement with experiment, neither static nor dynamical magnetic moments are predicted. In addition, the quasiparticle density of states reproduces not only the peak close to the Fermi level, which explains the large coefficient of electronic specific heat, but also main 5f features observed in photoelectron spectroscopy.

scholarly journals ONETEP + TOSCAM: Uniting Dynamical Mean Field Theory and Linear-Scaling Density Functional Theory

2020 ◽  
Vol 16 (8) ◽  
pp. 4899-4911
Author(s):  
Edward B. Linscott ◽  
Daniel J. Cole ◽  
Nicholas D. M. Hine ◽  
Michael C. Payne ◽  
Cédric Weber
Keyword(s):  
Field Theory ◽  
Density Functional Theory ◽  
Density Functional ◽  
Mean Field Theory ◽  
Mean Field ◽  
Dynamical Mean Field Theory ◽  
Linear Scaling ◽  
Functional Theory

scholarly journals Electronic Structure and Transport Properties of Superlattices: La(1-X)SrxTiO3 (X =0, 0.20, 0.80, 1)

2020 ◽  
Vol 6 (2) ◽  
pp. 134-148
Author(s):  
R. K. Rai ◽  
G. C. Kaphle ◽  
R. B. Ray ◽  
O. P. Niraula
Keyword(s):  
Field Theory ◽  
Phase Transition ◽  
Figure Of Merit ◽  
Density Functional ◽  
Chemical Potential ◽  
Mean Field Theory ◽  
Mean Field ◽  
Dynamical Mean Field Theory ◽  
Functional Theory ◽  
Metal Insulator

The conventional density functional theory (DFT) and dynamical mean field theory (DMFT) is used to study the structural, electronic and the Mott-Hubbard metal-insulator phase transition of the pristine and superstructures, La(1-x)SrxTiO3 (x = 0, 0.20, 0.80, 1). The electrical and thermal conductivities, Seebeck coefficient, Figure of merit are calculated using the BoltzTraP codes. The present study reveals that the direct band gap of 2.20 eV and indirect band gap ~2.0 eV at the Γ point in the Brillouin zone of SrTiO3 is upgraded to 3.423eV by using modified Beck-Johnson (mBJ) interaction potential. The metal-insulator transition (MIT) of LaTiO3 and the superlattice La(1-x)SrxTiO3 have been investigated by using conventional density functional theory (DFT) and dynamical mean field theory (DMFT). The Mott-Hubbard metal-insulator transitions for pristine LaTiO3 for a Coulombian parameter, U = 2.5 eV and the thermodynamic parameter β = 6 (eV)-1 are consistent with the experimental results. A typical set of these correlation parameters for MIT La0.20Sr0.80TiO3 and La0.80Sr0.20TiO3 systems are found to be U = 3.5 eV and β = 10(eV)-1 and U = 3.2 eV and β = 10 (eV)-1 respectively. The characteristic sharp quasi-particle peak for a sample of La0.80Sr0.20TiO3 superlattice systems is obtained correlation parameter U = 3.0 eV and β = 6(eV)-1. A thermoelectric phase transition is observed for Seebeck Coefficient at temperature 300 K at near chemical potential, μ = 1eV of SrTiO3. The corresponding figure of merit (ZT) with chemical potential (μ) appears to be unity at near μ = 1eV.

scholarly journals EQUATION-OF-MOTION APPROACH TO DYNAMICAL MEAN FIELD THEORY

2006 ◽  
Vol 20 (25) ◽  
pp. 1629-1636 ◽  
Author(s):  
JIAN-XIN ZHU ◽  
R. C. ALBERS ◽  
J. M. WILLS
Keyword(s):  
Field Theory ◽  
Mean Field Theory ◽  
Mean Field ◽  
Bethe Lattice ◽  
Equation Of Motion ◽  
Spectral Weight ◽  
Dynamical Mean Field Theory ◽  
Strongly Correlated ◽  
Strongly Correlated Materials ◽  
Weight Transfer

We propose using an equation-of-motion approach as an impurity solver for dynamical mean field theory. As an illustration of this technique, we consider a finite-U Hubbard model defined on the Bethe lattice with infinite connectivity at arbitrary filling. Depending on the filling, the spectra that is obtained exhibits a quasiparticle peak, and lower and upper Hubbard bands as typical features of strongly correlated materials. The results are also compared and in good agreement with exact diagonalization. We also find a different picture of the spectral weight transfer than the iterative perturbation theory.

Sign in / Sign up

Export Citation Format

Share Document