23 research outputs found
Probing eigenfunction nonorthogonality by parametric shifts of resonance widths
Recently, it has been shown that the change of resonance widths in an open system under a perturbation of its interior is a sensitive indicator of the nonorthogonality of resonance states. We apply this measure to quantify parametric motion of the resonances. In particular, a strong redistribution of the widths is linked with the maximal degree of nonorthogonality. Then for weakly open chaotic systems we discuss the effect of spectral rigidity on the statistical properties of the parametric width shifts, and derive the distribution of the latter in a picket-fence model with equidistant spectrum
Preempted phonon-mediated superconductivity in the infinite-layer nickelates
Nickelate superconductors are outstanding materials with intriguing analogies
with the cuprates. These analogies suggest that their superconducting mechanism
is similarly unconventional, although this fundamental question is currently
under debate. Here, we scrutinize the role played by electronic correlations in
enhancing the electron-phonon coupling in the infinite-layer nickelates and the
extent to which this may promote superconductivity. Specifically, we use
many-body perturbation theory to perform state-of-the-art and
Eliashberg-theory calculations. We find that the electron-phonon coupling is in
effect enhanced compared to density-functional-theory calculations. This
enhancement may lead to low- superconductivity in the parent compounds
already. However, it remains marginal in the sense that it cannot explain the
record s obtained with doping. Conventional superconductivity then appears
to be preempted by another mechanism in the infinite-layer nickelates.Comment: 6 pages, 4 figures, 1 table + Supplementary Informatio
Cooperative Inter-vehicle communication protocol dedicated to intelligent transport systems (CIVIC: Communication Inter Véhicule Intelligente et Coopérative)
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