Lattice dynamics of palladium in the presence of electronic correlations

Appelt, Wilhelm H.; Östlin, Andreas; Marco, Igor Di; Leonov, I.; Sekania, Michael; Vollhardt, D.; Chioncel, Liviu

doi:10.1103/physrevb.101.075120

Cited by 6 publications

(7 citation statements)

References 64 publications

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“…The wave-vectors at which the Kohn anomaly arise are the nesting vectors of the Fermi surface which for Pd are the tube structures along X − W direction. In contrast to DFT results, for which the phonon frequency remains essentially constant in a large temperature range, correlation effects reduce the restoring force of the ionic displacements at low temperatures, leading to a mode softening 22 .…”

Section: Introductioncontrasting

confidence: 67%

“…Using the same LDA+DMFT method we computed the changes in the phonon dispersions and phonon density of states of Pd under a hydro-static pressure. We found that electronic correlations at finite temperatures strongly renormalize the phonon frequencies and are the source of the so-called Kohn anomaly 22 . The wave-vectors at which the Kohn anomaly arise are the nesting vectors of the Fermi surface which for Pd are the tube structures along X − W direction.…”

Section: Introductionmentioning

confidence: 95%

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$L$-hole Pockets of the Palladium Fermi Surface Revealed by Positron Annihilation Spectroscopy

Sekania,

Östlin,

Appelt

et al. 2021

Preprint

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Using the combined Density Functional and Dynamical Mean Field theory we study relativistic corrections to the Fermi surface of palladium. We find indeed that relativistic corrections create a small hole pockets at the L-symmetry points. Furthermore we show that the computed two dimensional Angular Correlation of Electron Positron Annihilation Radiation (the so called 2D-ACAR) clearly demonstrates the existence of these L-hole pockets, which remains robust against electronic correlations. A 2D-ACAR experiment should therefore provide the "smoking-gun" proof for the existence of the L-hole pockets in the palladium Fermi surface.

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Section: Introductioncontrasting

confidence: 67%

Section: Introductionmentioning

confidence: 95%

$L$-hole Pockets of the Palladium Fermi Surface Revealed by Positron Annihilation Spectroscopy

Sekania,

Östlin,

Appelt

et al. 2021

Preprint

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“…The study of electron-phonon interactions (EPIs) goes back to the early days of solid-state theory. They are important for our understanding of basic material properties such as effective masses [1][2][3][4] and lattice constants [5,6]. Furthermore, this interaction is responsible for phase transitions, such as conventional superconductivity [7][8][9][10][11][12][13][14][15][16][17][18] and charge-density waves (CDWs) [19][20][21][22][23][24][25][26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Downfolding the Su-Schrieffer-Heeger model

et al. 2021

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Charge-density waves are responsible for symmetry-breaking displacements of atoms and concomitant changes in the electronic structure. Linear response theories, in particular density-functional perturbation theory, provide a way to study the effect of displacements on both the total energy and the electronic structure based on a single ab initio calculation. In downfolding approaches, the electronic system is reduced to a smaller number of bands, allowing for the incorporation of additional correlation and environmental effects on these bands. However, the physical contents of this downfolded model and its potential limitations are not always obvious. Here, we study the potential-energy landscape and electronic structure of the Su-Schrieffer-Heeger (SSH) model, where all relevant quantities can be evaluated analytically. We compare the exact results at arbitrary displacement with diagrammatic perturbation theory both in the full model and in a downfolded effective single-band model, which gives an instructive insight into the properties of downfolding. An exact reconstruction of the potential-energy landscape is possible in a downfolded model, which requires a dynamical electron-biphonon interaction. The dispersion of the bands upon atomic displacement is also found correctly, where the downfolded model by construction only captures spectral weight in the target space. In the SSH model, the electron-phonon coupling mechanism involves exclusively hybridization between the low- and high-energy bands and this limits the computational efficiency gain of downfolded models.

show abstract

“…The study of electron-phonon interactions (EPIs) goes back to the early days of solid state theory. They are important for our understanding of basic material parameters, like effective masses of electrons [1][2][3][4] and lattice constants [5,6]. Furthermore, this interaction is responsible for phase transitions, such as conventional superconductivity [7][8][9][10][11][12][13][14][15][16][17][18] and charge-density waves [19][20][21][22][23][24][25][26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Downfolding the Su-Schrieffer-Heeger model

Schobert,

Berges,

Wehling

et al. 2021

Preprint

View full text Add to dashboard Cite

Charge-density waves are responsible for symmetry-breaking displacements of atoms and concomitant changes in the electronic structure. Linear response theories, in particular density functional perturbation theory, provide a way to study the effect of displacements on both the total energy and the electronic structure based on a single ab-initio calculation. In downfolding approaches, the electronic system is reduced to a smaller number of bands, allowing for the incorporation of additional correlation and environmental effects on these bands. However, the physical contents of this downfolded model and its potential limitations are not always obvious. Here, we study the potential energy landscape and electronic structure of the Su-Schrieffer-Heeger (SSH) model, where all relevant quantities can be evaluated analytically. We compare the exact results at arbitrary displacement with diagrammatic perturbation theory both in the full model and in a downfolded effective single-band model, which gives an instructive insight into the properties of downfolding. An exact reconstruction of the potential energy landscape is possible in a downfolded model, which requires a dynamical electron-biphonon interaction. The dispersion of the bands upon atomic displacement is also found correctly, where the downfolded model by construction only captures spectral weight in the target space. In the SSH model, the electron-phonon coupling mechanism involves exclusively hybridization between the low-and high-energy bands and this limits the computational efficiency gain of downfolded models.

show abstract

Lattice dynamics of palladium in the presence of electronic correlations

Cited by 6 publications

References 64 publications

$L$-hole Pockets of the Palladium Fermi Surface Revealed by Positron Annihilation Spectroscopy

$L$-hole Pockets of the Palladium Fermi Surface Revealed by Positron Annihilation Spectroscopy

Downfolding the Su-Schrieffer-Heeger model

Downfolding the Su-Schrieffer-Heeger model

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