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Quantum cluster theories
Quantum cluster approaches offer new perspectives to study the complexities of macroscopic correlated fermion systems. These approaches can be understood as generalized mean-field theories. Quantum
Numerical renormalization group method for quantum impurity systems
In the early 1970s, Wilson developed the concept of a fully nonperturbative renormalization group transformation. When applied to the Kondo problem, this numerical renormalization group (NRG) method
Nonlocal Dynamical Correlations of Strongly Interacting Electron Systems
We introduce an extension of the dynamical mean-field approximation (DMFA) that retains the causal properties and generality of the DMFA, but allows for systematic inclusion of nonlocal corrections.
Effects of magnetic anisotropy on the subgap excitations induced by quantum impurities in a superconducting host
We study the magnetic anisotropy effects on the localized sub-gap excitations induced by quantum impurities coupled to a superconducting host. We establish the ground-state phase diagrams for
Realistic investigations of correlated electron systems with LDA + DMFT
Conventional band structure calculations in the local density approximation (LDA) [1–3] are highly successful for many materials, but miss important aspects of the physics and energetics of strongly
Theoretical description of time-resolved photoemission spectroscopy: application to pump-probe experiments.
The theory for time-resolved, pump-Probe, photoemission spectroscopy and other pump-probe experiments is developed, incorporating all of the nonequilibrium effects of the pump pulse and the finite time width of the probe pulse and including possibilities for taking into account band structure and matrix element effects, surface states, and the interaction of the photoexcited electrons with the system leading to corrections to the sudden approximation.
Energy resolution and discretization artifacts in the numerical renormalization group
We study the limits of the energy resolution that can be achieved in the calculations of spectral functions of quantum impurity models using the numerical renormalization group NRG technique with
Momentum-resolved spectral functions of SrVO 3 calculated by LDA + DMFT
$\mathrm{LDA}+\mathrm{DMFT}$, the merger of density functional theory in the local density approximation and dynamical mean-field theory, has been mostly employed to calculate