arXiv subjects

A. A. Nikolaev

Publications and source records attributed to A. A. Nikolaev.

22 records · Page 2Linked to original sources

arXiv2015

Lattice simulation of $QC_2D$ with $N_f=2$ at non-zero baryon density

The lattice simulations of $QC_2D$ with two flavors of staggered fermions and non-zero quark chemical potential $μ_q$ have been performed. Dependencies of the Polyakov loop, chiral condensate and baryon number density on $μ_q$ were studied. We found that an increase of the baryon chemical potential leads to chiral symmetry restoration. At small values of $μ_q$, our results for the baryon number density agree with ChPT predictions.

hep-lat↗

arXiv2015

On stationary solutions of KdV and mKdV equations

Stationary solutions on a bounded interval for an initial-boundary value problem to Korteweg--de~Vries and modified Korteweg--de~Vries equation (for the last one both in focusing and defocusing cases) are constructed. The method of the study is based on the theory of conservative systems with one degree of freedom. The obtained solutions turn out to be periodic. Exact relations between the length of the interval and coefficients of the equations which are necessary and sufficient for existence of nontrivial solutions are established.

math.AP↗

arXiv2014

Monte-Carlo study of the phase transition in the AA-stacked bilayer graphene

Tight-binding model of the AA-stacked bilayer graphene with screened electron-electron interactions has been studied using the Hybrid Monte Carlo simulations on the original double-layer hexagonal lattice. Instantaneous screened Coulomb potential is taken into account using Hubbard-Stratonovich transformation. G-type antiferromagnetic ordering has been studied and the phase transition with spontaneous generation of the mass gap has been observed. Dependence of the antiferromagnetic condensate on the on-site electron-electron interaction is examined.

cond-mat.str-el↗

arXiv2013

Interaction of static charges in graphene within Monte-Carlo simulation

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 lattice field theory with noncompact $3 + 1$-dimensional Abelian lattice gauge fields and $2 + 1$-dimensional staggered lattice fermions. It is shown that for all considered temperatures the interaction can be well described by the Debye screened potential created by two-dimensional electron-hole excitations. At low temperatures Debye mass $m_D$ plays a role of order parameter of the insulator-semimetal phase transition. In the semimetal phase at high temperature graphene reveals the properties of weakly interacting two-dimensional plasma of fermions excitations.

cond-mat.str-el↗