85 citations · 457 across the 22 of their papers we have counts for
18 papers · 1 filter
Validity of SLAC fermions for the (1 + 1)-dimensional helical Luttinger liquid
Zhenjiu Wang, Fakher Assaad, Maksim Ulybyshev
The Nielson-Ninomiya theorem states that a chirally invariant free fermion lattice action, which is local, translation invariant, and real necessarily has fermion doubling. The SLA…
Instanton gas approach to the Hubbard model
Maksim Ulybyshev, Christopher Winterowd, Fakher Assaad +1
In this article we consider a path integral formulation of the Hubbard model based on a SU(2)-symmetrical Hubbard-Stratonovich transformation that couples auxiliary field to the lo…
Mitigating spikes in fermion Monte Carlo methods by reshuffling measurements
Maksim Ulybyshev, Fakher Assaad
We propose a method to mitigate heavy-tailed distributions in fermion Quantum Monte Carlo simulations originating from zeros of the fermion determinant. In this case the second mom…
Bridging the gap between numerics and experiment in free standing graphene
Maksim Ulybyshev, Savvas Zafeiropoulos, Christopher Winterowd +1
We report results of large-scale quantum Monte Carlo (QMC) simulations of graphene. Using cutting-edge algorithmic improvements, we are able to consider spatial volumes, correspond…
Quantum phase transitions on the hexagonal lattice
Dominik Smith, Pavel Buividovich, Michael Körner +2
Hubbard-type models on the hexagonal lattice are of great interest, as they provide realistic descriptions of graphene and other related materials. Hybrid Monte Carlo simulations o…
Taming the sign problem of the finite density Hubbard model via Lefschetz thimbles
Maksim Ulybyshev, Christopher Winterowd, Savvas Zafeiropoulos
We study the sign problem in the Hubbard model on the hexagonal lattice away from half-filling using the Lefschetz thimbles method. We identify the saddle points, reduce their amou…
Lefschetz thimbles decomposition for the Hubbard model on the hexagonal lattice
Maksim Ulybyshev, Christopher Winterowd, Savvas Zafeiropoulos
We propose a framework to study the properties of the Lefschetz thimbles decomposition for lattice fermion models approaching the thermodynamic limit. The proposed set of algorithm…
Numerical evidence of conformal phase transition in graphene with long-range interactions
Pavel Buividovich, Dominik Smith, Maksim Ulybyshev +1
Using state of the art Hybrid-Monte-Carlo (HMC) simulations we carry out an unbiased study of the competition between spin-density wave (SDW) and charge-density wave (CDW) order in…
Hybrid-Monte-Carlo study of competing order in the extended fermionic Hubbard model on the hexagonal lattice
Pavel Buividovich, Dominik Smith, Maksim Ulybyshev +1
Using first-principle Hybrid-Monte-Carlo (HMC) simulations, we carry out an unbiased study of the competition between spin-density wave (SDW) and charge-density wave (CDW) order in…
Schur complement solver for Quantum Monte-Carlo simulations of strongly interacting fermions
Maksim Ulybyshev, Nils Kintscher, Karsten Kahl +1
We present a non-iterative solver based on the Schur complement method for sparse linear systems of special form which appear in Quantum Monte-Carlo (QMC) simulations of strongly i…
Path integral representation for the Hubbard model with reduced number of Lefschetz thimbles
M. V. Ulybyshev, S. N. Valgushev
The concept of Lefschetz thimble decomposition is one of the most promising possible modifications of Quantum Monte Carlo (QMC) algorithms aimed at alleviating the sign problem whi…
Quantum Monte Carlo study of static potential in graphene
N. Yu. Astrakhantsev, V. V. Braguta, M. I. Katsnelson +2
In this paper the interaction potential between static charges in suspended graphene is studied within the quantum Monte Carlo approach. We calculated the dielectric permittivity o…
Collective charge excitations and the metal-insulator transition in the square lattice Hubbard-Coulomb model
Maksim Ulybyshev, Christopher Winterowd, Savvas Zafeiropoulos
In this article, we discuss the non-trivial collective charge excitations (plasmons) of the extended square-lattice Hubbard model. Using a fully non-perturbative approach, we emplo…
A Hybrid-Monte-Carlo study of monolayer graphene with partially screened Coulomb interactions at finite spin density
Michael Körner, Dominik Smith, Pavel Buividovich +2
We report on Hybrid-Monte-Carlo simulations at finite spin density of the -band electrons in monolayer graphene with realistic inter-electron interactions. Unlike simulations at…
Inter-electron interactions and the RKKY potential between H adatoms in graphene
Pavel Buividovich, Dominik Smith, Maksim Ulybyshev +1
We use first-principles Quantum Monte-Carlo simulations to study the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between hydrogen adatoms attached to a graphene sheet. We find…
Many-body effects on graphene conductivity: Quantum Monte Carlo calculations
D. L. Boyda, V. V. Braguta, M. I. Katsnelson +1
Optical conductivity of graphene is studied using Quantum Monte Carlo calculations. We start from Euclidean current-current correlator and extract from Green-Kubo relations…
Interaction of static charges in graphene within Monte-Carlo simulation
V. V. Braguta, S. N. Valgushev, A. A. Nikolaev +2
The study of the interaction potential between static charges within Monte-Carlo simulation of graphene is carried out. The numerical simulations are performed in the effective lat…
Numerical study of the conductivity of graphene monolayer within the effective field theory approach
P. V. Buividovich, E. V. Luschevskaya, O. V. Pavlovsky +2
We report on the direct numerical measurements of the conductivity of graphene monolayer. Our numerical simulations are performed in the effective lattice field theory with noncomp…