arXiv subjects

N. A. Asriyan

Publications and source records attributed to N. A. Asriyan.

8 recordsLinked to original sources

arXiv2026

A phenomenological universal expression for the condensate fraction in strongly-correlated two-dimensional Bose gases

We investigate the relation between non-local and energetic properties in two-dimensional quantum systems of zero-temperature bosons. By analyzing numerous interaction potentials across densities spanning from perturbative to the strongly correlated regime, we discover a novel high-precision quantum phenomenological universality: the condensate fraction can be expressed through kinetic energy and quantum energy, defined as total energy relative to the classical crystal state. Quantum Monte Carlo simulations accurately validate our analytical expression. Furthermore, we test the obtained relation on the fundamental example of a non-perturbative system, namely, liquid helium. The proposed relation is relevant to experiments with excitons in transition metal dichalcogenides (TMDC) materials, as well as ultracold atoms and other quantum systems in reduced dimensionality.

cond-mat.quant-gas↗

arXiv2026

Generating entangled polaritonic condensates by pumping with entangled pairs of photons

We investigate the steady state of two single-mode uniform spatially separated polaritonic conden- sates exposed to resonant pumping with entangled pairs of photons. We demonstrate the principal possibility of driving the system to an entangled state despite its exposure to noises arising from the excitonic reservoir and photon leakage through the microcavity mirrors. Estimates are provided for the flux of entangled particles required to drive the system into a steady state that violates the partial-transpose criterion for entanglement. Furthermore, we trace the evolution of the system after a sudden disappearance of the entangled pumping. Our analysis provides estimates for the entanglement lifetime in a system of two exciton-polariton condensates

quant-ph↗

arXiv2025

Phase alignment in a lattice of exciton-polaritonic Bose-Einstein condensates

Dynamics of exciton-polariton Bose-Einstein condensate is examined by means of the stochastic Gross-Pitaevskii equation including non-Markovian coupling to the excitonic reservoir. Attention is concentrated on properties of the condensate lattice created by laser beams providing incoherent pumping of the reservoir. It is shown that phase ordering of the lattice depends on temperature. The crossover between the in-phase (``ferromagnetic'') and the checkboard (``antiferromagnetic'') orders is accompanied by variation of the steady-state condensate density. Also it is shown that the condensate lattices can retain ordered pattern for temperatures which are much higher than the critical temperature of a single spot, probably due to suppression of the modulational instability.

cond-mat.quant-gas↗

arXiv2025

Finite-size effects in two-photon correlations of exciton Bose-Einstein condensates

Accessing two-photon statistics via Hunbary Brown and Twiss (HBT)-type measurements is essential for investigations of excitonic Bose-condensates. In this paper we make use of quantum hydrodynamics in order to study the finite-size impact on the two-photon emission intensity of a 2D condensate of excitons. We use the developed approach to calculate the two-photon decay time of exciton condensate in GaAs quantum wells and MoS$_2$ bilayers. We demonstrate that the registered signal scales on the sample size in a qualitatively different manner than the Bogoliubov theory predicts.

cond-mat.quant-gas↗

arXiv2024

Stochastic model for assesing coherent properties of polariton condensates

By considering a microscopical model, we derive an evolution equation for single-mode polariton condensate taking into account the fluctuations of the order parameter. We use it to derive an analytical expression for the second order correlation function and the share of coherent occupation of the condensate in presence of pumping-leakage balance.

cond-mat.quant-gas↗

arXiv2023

Mean field study of 2D quasiparticle condensate formation in presence of strong decay

Bose-condensation in a system of 2D quasiparticles is considered in the scope of a microscopic model. Mean-field dynamical equations are derived with the help of the Schwinger-Keldysh formalism and a simple model is proposed which allows to describe key features of condensate formation in systems with various quasiparticle decay rates. By analysing stationary solutions of this equation, we obtain the phase diagram of quasiparticle gas, finding a bistability region in the parameter space of the system. Finally, as an application of our theory, we study the phase diagram of a 2D exciton-polariton system in CdTe microcavity.

cond-mat.quant-gas↗

arXiv2022

Non-Markovian stochastic Gross-Pitaevskii equation for the exciton-polariton Bose-Einstein condensate

In this paper, a non-Markovian Gross-Pitaevskii equation is proposed to describe the formation of a condensate in an exciton-polariton system under incoherent pumping. By introducing spatially delta-correlated noise terms, we observe a transition from a spatially ordered phase to a disordered one as the temperature increases. In course of this process, the population of the condensate is significantly reduced. Irregularly located separate dense spots of condensate above the transition temperature are revealed. Using the Gabor transform, it is shown that, with increasing temperature, the condensate decoheres, that is accompanied by the transition from narrowband to broadband spectral density.

cond-mat.quant-gas↗

arXiv2019

Optical probing in a bilayer dark-bright condensate system

We consider a bilayer system of two-dimensional Bose-Einstein-condensed dipolar dark excitons (upper layer) and bright ones (bottom layer). We demonstrate that the interlayer interaction leads to a mixing between excitations from different layers. This mixing leads to the appearance of a second spectral branch in the spectrum of bright condensate. The excitation spectrum of the condensate of dark dipolar excitons then becomes optically accessible during luminescence spectra measurements of the bright condensate, which allows one to probe its kinetic properties. This approach is relevant for experimental setups, where detection via conventional techniques remains challenging; in particular, the suggested method is useful for studying dark dipolar excitons in transition metal dichalcogenide monolayers.

cond-mat.quant-gas↗