144 citations · 267 across the 11 of their papers we have counts for
8 papers · 1 filter
Real-Frequency Diagrammatics with Pole Representations
Rayan Farid, Lei Zhang, Aiman Al-Eryani +2
Finite-temperature many-body theories are typically formulated in imaginary time, where they are amenable to efficient numerical treatment. However, the extraction of spectral prop…
Minimal pole representation for spectral functions
Lei Zhang, André Erpenbeck, Yang Yu +1
Representing spectral densities, real-frequency, and real-time Green's functions of continuous systems by a small discrete set of complex poles is an ubiquitous problem in condense…
Minimal pole representation and analytic continuation of matrix-valued correlation functions
Lei Zhang, Yang Yu, Emanuel Gull
We present a minimal pole method for analytically continuing matrix-valued imaginary frequency correlation functions to the real axis, enabling precise access to off-diagonal eleme…
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-…
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…
Minimal Pole Representation and Controlled Analytic Continuation of Matsubara Response Functions
Lei Zhang, Emanuel Gull
Analytical continuation is a central step in the simulation of finite-temperature field theories in which numerically obtained Matsubara data is continued to the real frequency axi…
Role of three-particle vertex within dual fermion calculations
T. Ribic, P. Gunacker, S. Iskakov +5
We investigate the influence of self-energy diagrams beyond the two-particle vertex level within dual fermion theory. Specifically, we calculate the local three-particle vertex and…
Fluctuation diagnostics of the electron self-energy: Origin of the pseudogap physics
O. Gunnarsson, T. Schäfer, J. P. F. LeBlanc +5
We demonstrate how to identify which physical processes dominate the low-energy spectral functions of correlated electron systems. We obtain an unambiguous classification through a…