arXiv subjects

Ruslan Mushkaev

Publications and source records attributed to Ruslan Mushkaev.

4 recordsLinked to original sources

arXiv2026

Strange metallicity in the Kagome metal Ni$_3$In: a DMFT investigation

Strange metallicity, characterized by a linear temperature dependence of the resistivity, is observed in a broad range of correlated materials, including heavy-fermion compounds and cuprate superconductors. It has also recently been reported for the Kagome metal Ni$_3$In, where almost localized and itinerant electronic degrees of freedom coexist as a result of a partially flat band. We investigate the correlated electronic structure and transport properties of Ni$_3$In with dynamical mean field theory (DMFT) calculations performed on a minimal single-band Hubbard model, constructed from compact molecular orbitals. Despite the large band filling, even for moderate Hubbard repulsion, we observe a non-Fermi-liquid like frequency dependence of the self-energy, as well as the formation of local magnetic moments. With increased hole doping, a crossover to a heavy Fermi-liquid regime is found. We interpret these results in terms of an effective model for the partially filled narrow band near $k_z=0$.

cond-mat.str-el↗

arXiv2025

Spin-stripes in the Hubbard model: a combined DMFT and Bethe-Salpeter analysis

The Hubbard model is known to accommodate various electronic orders, including stripes, which are important for understanding the physics of cuprates. We study spin-stripe order in the square lattice Hubbard model as a function of doping and temperature, by solving the Bethe-Salpeter equation with the local vertex from dynamical mean field theory (DMFT), both inside and outside the antiferromagnetic phase. We find broad regions of horizontal/vertical spin stripes at low temperatures for the model with and without next-nearest neighbor hopping. Their wavelength depends on hole doping in a nonlinear fashion, and is highly sensitive to the ratio of nearest and next-nearest neighbor hoppings.

cond-mat.str-el↗

arXiv2024

Semiclassical origin of suppressed quantum chaos in Rydberg chains

The surprisingly long-lasting oscillations observed in the dynamics of highly excited states of chains of Rydberg atoms defy the expectation that interacting systems should thermalize fast. The phenomenon is reminiscent of wavepackets in quantum billiards that trace classical periodic orbits. While analogs of the associated scarred eigenfunctions have been found for Rydberg chains, an underlying classical limit hosting periodic orbits has remained elusive. Here we generalize the Rydberg (pseudospin $S=1/2$) system to a chain of arbitrary spin $S$. Its classical limit features unexpectedly stable periodic orbits that are essential to understand the emergence of robust, parametrically suppressed quantum chaoticity, with semi-classical coherence times diverging as $\sqrt{S}$. The classical limit successfully explains several empirical features of the quantum limit.

quant-ph↗

arXiv2024

Internal consistency of multi-tier $GW$+EDMFT

The multi-tier $GW$+EDMFT scheme is an ab-initio method for calculating the electronic structure of correlated materials. While the approach is free from ad-hoc parameters, it requires a selection of appropriate energy windows for describing low-energy and strongly correlated physics. In this study, we test the consistency of the multi-tier description by considering different low-energy windows for a series of cubic SrXO$_3$ (X=V,Cr,Mn) perovskites. Specifically, we compare the 3-orbital $t_{2g}$ model, the 5-orbital $t_{2g}+e_g$ model, the 12-orbital $t_{2g}+O_p$ model, and (in the case of SrVO$_3$) the 14-orbital $t_{2g}+e_g+O_p$ model and compare the results to available photoemission and X-ray absorption measurements. The multi-tier method yields consistent results for the $t_{2g}$ and $t_{2g}+e_g$ low-energy windows, while the models with $O_p$ states produce stronger correlation effects and mostly agree well with experiment, especially in the unoccupied part of the spectrum. We also discuss the consistency between the fermionic and bosonic spectral functions and the physical origin of satellite features, and present momentum-resolved charge susceptibilities.

cond-mat.str-el↗