6 papers · 1 filter
Two distinct gap structures in the mid-infrared optical conductivity of the Hubbard model
Dongwook Kim, Karsten Held
Mid-infrared (MIR) optical conductivities in cuprate superconductors show universal features. In this study, we demonstrate that these originate from two distinct gaps: the pseudog…
Symmetric estimator for discrete self-energy of discrete many-body systems
Aleksandrs Zacinskis, Frank T. Ebel, Mathias Pelz +5
We derive a discrete spectral representation of the single-particle self-energy using a discrete evaluation of Kugler's symmetric improved estimator. Our construction can be used o…
Pairing boost from enhanced spin-fermion coupling in the pseudogap regime
Yang Yu, Sergei Iskakov, Emanuel Gull +2
We perform a fluctuation analysis of the pairing interaction in the hole-doped Hubbard model within the dynamical cluster approximation. Our analysis reveals that spin-fluctuation-…
Embedded multi-boson exchange: A step beyond quantum cluster theories
Dominik Kiese, Nils Wentzell, Igor Krivenko +3
We introduce a diagrammatic multi-scale approach to the Hubbard model based on the interaction-irreducible (multi-boson) vertex of a small cluster embedded in a self-consistent med…
Unambiguous fluctuation decomposition of the self-energy: pseudogap physics beyond spin fluctuations
Yang Yu, Sergei Iskakov, Emanuel Gull +2
Correlated electron systems may give rise to multiple effective interactions whose combined impact on quasiparticle properties can be difficult to disentangle. We introduce an unam…
Overcomplete intermediate representation of two-particle Green's functions and its relation to partial spectral functions
Selina Dirnböck, Seung-Sup B. Lee, Fabian B. Kugler +4
Two-particle response functions are a centerpiece of both experimental and theoretical quantum many-body physics. Yet, due to their size and discontinuity structure, they are chall…