27 citations · 43 across the 10 of their papers we have counts for
10 papers
Instabilities in self-consistent diagrammatic approaches and how to cure them
Marcel Gievers, Herbert Eßl, Stefan Rohshap +2
While self-consistent diagrammatic approaches are widely used to compute the physical properties of correlated quantum materials, their applicability may get severely hindered prec…
Stabilizing the parquet problem
Herbert Eßl, Stefan Rohshap, Marcel Gievers +3
We systematically analyze the stability of the iterative solution of the parquet equations by studying the spectrum of the Jacobian associated with the commonly used damped fixed-p…
Probing Bardeen-Cooper-Schrieffer pairing and quasiparticle formation in ultracold gases by Rydberg atom spectroscopy
Emilio Ramos Rodríguez, Marcel Gievers, Richard Schmidt
Locally probing pairing in fermionic superfluids, ranging from micro- to macroscopic scales, has been a long-standing challenge. Here, we investigate a new approach that uses Rydbe…
Functional renormalization with interaction flows: A single-boson exchange perspective and application to electron-phonon systems
Aiman Al-Eryani, Marcel Gievers, Kilian Fraboulet
The functional renormalization group (fRG) is acknowledged as a powerful tool in quantum many-body physics and beyond. On the technical side, conventional implementations of the fR…
Single-boson exchange formulation of the Schwinger-Dyson equation and its application to the functional renormalization group
Miriam Patricolo, Marcel Gievers, Kilian Fraboulet +6
We extend the recently introduced single-boson exchange formulation to the computation of the self-energy from the Schwinger--Dyson equation (SDE). In particular, we derive its exp…
Subleading logarithmic behavior in the parquet formalism
Marcel Gievers, Richard Schmidt, Jan von Delft +1
The Fermi-edge singularity in x-ray absorption spectra of metals is a paradigmatic case of a logarithmically divergent perturbation series. Prior work has thoroughly analyzed the l…
Quantum wires with local particle loss: Transport manifestations of fluctuation-induced effects
Marcel Gievers, Thomas Müller, Heinrich Fröml +2
We investigate the transport properties of a quantum wire of weakly interacting fermions in the presence of local particle loss. We calculate current and conductance in this system…
Probing polaron clouds by Rydberg atom spectroscopy
Marcel Gievers, Marcel Wagner, Richard Schmidt
In recent years, Rydberg excitations in atomic quantum gases have become a successful platform to explore quantum impurity problems. A single impurity immersed in a Fermi gas leads…
Multiloop flow equations for single-boson exchange fRG
Marcel Gievers, Elias Walter, Anxiang Ge +2
The recently introduced single-boson exchange (SBE) decomposition of the four-point vertex of interacting fermionic many-body systems is a conceptually and computationally appealin…
Shape effects of localized losses in quantum wires: dissipative resonances and nonequilibrium universality
Thomas Müller, Marcel Gievers, Heinrich Fröml +2
We study the effects of the spacial structure of localized losses in weakly-interacting fermionic quantum wires. We show that multiple dissipative impurities give rise to resonant…