23 research outputs found
Entangled magnetic, charge, and superconducting pairing correlations in the two-dimensional Hubbard model: a functional renormalization-group analysis
Using the recently introduced multiloop extension of the functional
renormalization group, we compute the magnetic, density, and superconducting
susceptibilities of the two-dimensional Hubbard model at weak coupling and
present a detailed analysis of their evolution with temperature, interaction
strength, and loop order. By breaking down the susceptibilities into
contributions from the bare susceptibility and the individual channels, we
investigate their relative importance as well as the channel interplay. In
particular, we trace the influence of antiferromagnetic fluctuations on the
-wave superconductivity and provide an analytical understanding for the
observed behavior.Comment: 31 pages, 19 figure
The Potential Use of Electrochemotherapy in the Treatment of Uveal Melanoma: In Vitro Results in 3D Tumor Cultures and In Vivo Results in a Chick Embryo Model
Uveal melanoma (UM) is the most common primary intraocular tumor that arises from neoplastic melanocytes in the choroid, iris, and ciliary body. Electrochemotherapy (ECT) has been successfully established for the treatment of skin and soft tissue metastatic lesions, deep-seated tumors of the liver, bone metastases, and unresectable pancreas lesions. The aim of this study was to evaluate the effect of ECT in vitro in 3D spheroid culture systems in primary and metastatic UM cell lines. We also investigated the chick embryo chorioallantoic membrane (CAM) as an in vivo model system for the growth and treatment of UM tumors using ECT. The cytotoxic effect of ECT in 3D spheroids was analyzed seven days following treatment by assessment of the size and MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction] assay. The cytotoxicity of ECT after intratumoral or intraarterial administration was evaluated histologically. In vitro and in vivo ECT caused a significant reduction in tumor size and viability compared to electroporation or chemotherapy in both sections of our study. The current results underline the effectiveness of ECT in the treatment of UM and prepare the way for further investigation of its potential application in UM
Mott transition and pseudogap of the square-lattice Hubbard model: results from center-focused cellular dynamical mean-field theory
The recently proposed center-focused post-processing procedure [Phys. Rev.
Research 2, 033476 (2020)] of cellular dynamical mean-field theory suggests
that central sites of large impurity clusters are closer to the exact solution
of the Hubbard model than the edge sites. In this paper, we systematically
investigate results in the spirit of this center-focused scheme for several
cluster sizes up to in and out of particle-hole symmetry. First we
analyze the metal-insulator crossovers and transitions of the half-filled
Hubbard model on a simple square lattice. We find that the critical interaction
of the crossover is reduced with increasing cluster sizes and the critical
temperature abruptly drops for the cluster. Second, for this
cluster size, we apply the center-focused scheme to a system with more
realistic tight-binding parameters, investigating its pseudogap regime as a
function of temperature and doping, where we find doping dependent
metal-insulator crossovers, Lifshitz transitions and a strongly renormalized
Fermi-liquid regime. Additionally to diagnosing the real space origin of the
suppressed antinodal spectral weight in the pseudogap regime, we can infer
hints towards underlying charge ordering tendencies.Comment: 29 pages, 15 figure
Single-boson exchange functional renormalization group application to the two-dimensional Hubbard model at weak coupling
We illustrate the algorithmic advantages of the recently introduced
single-boson exchange (SBE) formulation for the one-loop functional
renormalization group (fRG), by applying it to the two-dimensional Hubbard
model on a square lattice. We present a detailed analysis of the fermion-boson
Yukawa couplings and of the corresponding physical susceptibilities by studying
their evolution with temperature and interaction strength, both at half filling
and finite doping. The comparison with the conventional fermionic fRG
decomposition shows that the rest functions of the SBE algorithm, which
describe correlation effects beyond the SBE processes, play a negligible role
in the weak-coupling regime above the pseudo-critical temperature, in contrast
to the rest functions of the conventional fRG. Remarkably, they remain finite
also at the pseudo-critical transition, whereas the corresponding rest
functions of the conventional fRG implementation diverge. As a result, the SBE
formulation of the fRG flow allows for a substantial reduction of the numerical
effort in the treatment of the two-particle vertex function, paving a promising
route for future multiboson and multiloop extensions
Single-boson exchange functional renormalization group application to the two-dimensional Hubbard model at weak coupling
Mott transition and pseudogap of the square-lattice Hubbard model: Results from center-focused cellular dynamical mean-field theory
The recently proposed center-focused post-processing procedure [Phys. Rev. Res. 2, 033476 (2020)] of cellular dynamical mean-field theory suggests that central sites of large impurity clusters are closer to the exact solution of the Hubbard model than the edge sites. In this paper, we systematically investigate results in the spirit of this center-focused scheme for several cluster sizes up to 8Ă—8 in and out of particle-hole symmetry. First we analyze the metal-insulator crossovers and transitions of the half-filled Hubbard model on a simple square lattice. We find that the critical interaction of the crossover is reduced with increasing cluster sizes and the critical temperature abruptly drops for the 4Ă—4 cluster. Second, for this cluster size, we apply the center-focused scheme to a system with more realistic tight-binding parameters, investigating its pseudogap regime as a function of temperature and doping, where we find doping dependent metal-insulator crossovers, Lifshitz transitions and a strongly renormalized Fermi-liquid regime. Additionally to diagnosing the real space origin of the suppressed antinodal spectral weight in the pseudogap regime, we can infer hints towards underlying charge ordering tendencies