arXiv subjects

Abdelaali Boudjemaa

Publications and source records attributed to Abdelaali Boudjemaa.

At least 19 recordsLinked to original sources

arXiv2026

Modeling dark matter as self-bound quantum liquid droplets

The Bose-Einstein condensate dark matter model, where dark matter can be thought of as a non-relativistic, Newtonian gravitational condensate, has recently attracted a great deal of interest. In the present study, we explore the possibility that the dark matter could exist in the form of a self-bound quantum droplet formed by ultradilute quantum Bose mixtures under the action of Lee-Huang-Yang corrections at zero temperature. To this end, we derive an extended equation of state by using the nonrelativistic self-consistent Hartree-Fock-Bogoliubov theory and the hydrodynamic approach. The solutions of the obtained equations of state show that the key parameters of the dark matter halos such as the density, mass, and radius are sensitive to the interspecies interaction and to the quantum fluctuation strength. The stability and the dynamical evolution of the droplet Galactic halos are analyzed by considering small perturbations of the quantum hydrodynamical equations. In order to increase the reliability of our predictions we compare them with some observed data for the Galactic rotation curves.

gr-qc↗

arXiv2025

Quantum nature of gravity in self-bound quantum droplets

We explore the possibility of testing the quantum nature of the gravitational field with an ultracold self-bound quantum droplet of one-dimensional Bose-Bose mixtures. To this end, we solve variationally and numerically the underlying generalized Gross-Pitaevskii equation which includes the effects of quadratic and cubic nonlinearities. We derive the associated generalized uncertainty principle and its corresponding minimal length. The obtained modified uncertainty relation enables us to search for the quantum gravity signatures in both small and large droplets. We place bounds on the parameter using existing experimental data from recent experiment of dilute droplets of potassium. Improved upper bounds on the generalized uncertainty principle parameters are found from our analysis.

cond-mat.quant-gas↗

arXiv2025

Quench dynamics of disordered quadrupolar Bose-Einstein condensates

We systematically investigate the equilibrium and the nonequilibrium quench dynamics of three-dimensional disordered quadrupolar Bose-Einstein condensates. Within the Bogoliubov-Huang-Meng approximation, we show that the combined effect of quenched interactions, disorder and excitations may modify the static as well as the dynamic properties of the system. The validity criterion of the developed approach is accurately established. By quenching the interaction strength, we reveal that the quantum depletion and the deformation condensate induced by disorder are enhanced in the asymptotic steady state compared to the corresponding equilibrium values. The time evolution of the condensate deformation is accompanied by damped oscillations with amplitudes strongly depend on the disorder correlation length and on the relative quadrupolar interaction.

cond-mat.dis-nn↗

arXiv2025

Nonequilibrium quench dynamics of Bose-Einstein condensates of microwave-shielded polar molecules

We theoretically investigate the non-equilibrium dynamics of homogeneous ultracold Bose gases of microwave-shielded polar molecules following a sudden quench of the scattering length at zero temperature. We calculate in particular the quantum depletion, the anomalous density, the condensate fluctuations, and the pair correlation function using both the time-dependent Bogoliubov approach and the self-consistent time-dependent Hartree-Fock-Bogoliubov approximation. During their time evolution, these quantities exhibit slow or fast oscillations depending on the strength of the shielding interactions. We find that at long time scales the molecular condensate is characterized by nonequilibrium steady-state momentum distribution functions, with depletion, anomalous density and correlations that deviate from their corresponding equilibrium values. We demonstrate that the pair correlations expand diffusively at short times while they spread ballistically at long times.

cond-mat.quant-gas↗

arXiv2025

Quantum information flow in impurity qubits interacting with Bose-Bose mixtures

We investigate the dynamics of quantum information flow in one and two impurity qubits trapped in a double-well potential and interacting with a one-dimensional ultracold Bose-Bose mixture reservoir. For a single qubit immersed in a binary Bose mixture, we show that the system maintains coherence over finite timescales and exhibits non-Markovian dynamics, particularly in the upper branch of the environment. We explore the transition from Markovian to non-Markovian dephasing through the Ohmicity of the spectral density functions, which are significantly influenced by interspecies interactions. In the case of two spatially separated qubits coupled to the Bose-Bose mixture reservoir, we demonstrate that collective decoherence affects the system dynamics, leading to prolonged coherence survival in both branches of the mixture. The intricate evolution of the decoherence factors is reflected in the density spectral functions and their Ohmicity characteristics. We find that the decoherence functions and spectra oscillate with increasing distance between the qubits, modifying the information flow dynamics. Additionally, we conduct a thorough investigation of the entanglement dynamics between the two qubits induced by the binary Bose mixture reservoir in both branches, underscoring the critical role of interspecies interactions.

quant-ph↗

arXiv2025

Testing quantum gravity with dilute dipolar Bose gases

We systematically investigate the effects of quantum gravity on the ground-state properties of dilute homogeneous dipolar Bose gases using the Hartree-Fock-Bogoliubov theory based on the generalized uncertainty principle. We calculate quantum gravity corrections to the condensed fraction, the equation of state, the critical temperature and the superfluid fraction. Improved upper bounds on the generalized uncertainty principle parameters are found. We compare our predictions with previous experimental and theoretical results.

gr-qc↗

arXiv2024

Collapsing dynamics of attractive Bose-Einstein condensates in random potentials

We study the stationary and dynamical properties of three-dimensional trapped Bose-Einstein condensates with attractive interactions subjected to a random potential. To this end, a variational method is applied to solve the underlying Gross-Pitaevskii equation. We derive analytical predictions for the energy, the equilibrium width, and evolution laws of the condensate parameter. The breathing mode oscillations frequency of the condensate has been also calculated in terms of the gas and disorder parameters. We analyze in addition the dynamics of collapse from the Gaussian approximation. Surprisingly, we find that the intriguing interplay of the attractive interaction and disorder effects leads to prevent collapse of the condensate.

cond-mat.quant-gas↗

arXiv2024

Anderson localization of elementary excitations in disordered binary Bose mixtures: Effects of the Lee-Huang-Yang quantum and thermal corrections

We investigate analytically and numerically the Anderson localization of quasiparticles in binary Bose mixtures in the presence of the Lee-Huang-Yang quantum and thermal corrections subjected to correlated disordered potentials. We calculate the density profiles, the Bogoliubov quasiparticles modes, and the localization length in both the mixture and droplet phases. We show that for one-dimensional speckle potentials, the peculiar interplay of disorder and the Lee-Huang-Yang fluctuations may enhance localization in one component while inducing delocalization in the other. Our results reveal also that thermal fluctuations lead to the emergence of two and multiple localization maxima. In the droplet state, our findings uncover that the Anderson localization of quasiparticles is weak in the flat-top region since its excitation modes are restricted to those below the particle-emission threshold.

cond-mat.quant-gas↗

arXiv2023

Quantum liquid droplets in Bose mixtures with weak disorder

We study the properties of self-bound liquid droplets of three-dimensional Bose mixtures in a weak random potential with Gaussian correlation function at both zero and finite temperatures. Using the Bogoliubov theory, we derive useful formulas for the ground-state energy, the equilibrium density, the depletion, and the anomalous density of the droplet. The quantum fluctuation induced by the disorder known as the glassy fraction is also systematically computed. At finite temperature, we calculate the free energy, the thermal equilibrium density, and the critical temperature in terms of the disorder parameters. We show that when the strength and the correlation length of the disorder potential exceed a certain critical value, the droplet evaporates and is eventually entirely destroyed. We calculate the density profiles of this exotic state by means of numerical simulations of the corresponding generalized disorder Gross-Pitaevskii equation. Our predictions reveal that as the strength of the disorder gets larger, the atomic density varies rapidly in the plateau region. We point out in addition that the peculiar interplay of the disorder and the repulsive Lee-Huang-Yang corrections play a pivotal role in the collective modes of the self-bound droplet.

cond-mat.quant-gas↗

arXiv2023

A charged Coulomb Bose gas with dipole-dipole interactions

We systematically study the properties of a charged Coulomb Bose gas with dipole-dipole interactions in the weak coupling limit at both zero and finite temperatures using the Hartree-Fock-Bogoliubov approach. We numerically analyze the collective excitations, the condensate fraction, the depletion, the chemical potential, and the static structure factor. Moreover, we compare our new findings with those of nondipolar charged Coulomb Bose gas. Our results reveal that the complex interplay of Coulomb and dipole-dipole interactions may modify the stability, the thermodynamics and the coherence of the system.

cond-mat.quant-gas↗

arXiv2023

Anisotropy effects on the quantum transport of atomic matter waves

We discuss effects of anisotropic scattering in transport properties of ultracold atoms in three-dimensional optical potentials. Within the realm of the first Born approximation, we calculate the self energy, the scattering mean free time, the scattering mean free path, and the anisotropy factor. The behavior of the diffusion constant as a function of the wavenumber is also examined in diffusive and weak localization regimes. We show that these quantities are affected by quantum corrections due to the interference caused by disorder. The dimensionless conductance is also evaluated using the scaling theory of localization. Our results are compared with previous theoretical and the experimental results.

cond-mat.dis-nn↗

arXiv2023

Quantum localization corrections from the Bethe-Salpeter equation

We investigate coherent matter wave transport in isotropic 3D speckle potentials by using the Bethe-Salper equation and the self-consistent theory of localization. This model constitutes an efficient tool to properly evaluate corrections to Boltzmann diffusion by taking into consideration quantum interference terms between the multiple-scattering paths. We calculate analytically and numerically the static current density, the density of states, the dipolar contribution and the reduced diffusion coefficient. Our results reveal that quantum corrections to diffusive transport, known as weak localization may not only lead to shift the above quantities but affect also the position of the mobility edge.

cond-mat.dis-nn↗

arXiv2022

Moving Bose mixtures with dipole-dipole interactions

We study the properties of moving uniform dipolar Bose-Bose mixtures using the full Hartree-Fock-Bogoliubov theory. The analytical and numerical calculations emphasize that the competition between the relative motion of two fluids and the interspecies dipole-dipole interactions may affect the behavior of the condensed depletion, the anomalous density, the ground-state energy and second-order pair correlation. It is found that in the lower branch of the mixture, these quantities are unimportant and present an unconventional behavior.

cond-mat.quant-gas↗

arXiv2022

Weakly interacting Bose gases with generalized uncertainty principle: Effects of quantum gravity

We investigate quantum gravity corrections due to the generalized uncertainty principle on three-dimensional weakly interacting Bose gases at both zero and finite temperatures using the time-dependent Hatree-Fock-Bogoliubov theory. We derive useful formulas for the depletion, the anomalous density and some thermodynamic quantities such as the chemical potential, the ground-state energy, the free energy, and the superfluid density. It is found that the presence of a minimal length leads to modify the fluctuations of the condensate and its thermodynamic properties in the weak and strong quantum gravitational regimes. Unexpectedly, the interplay of quantum gravity effects and quantum fluctuations stemming from interactions may lift both the condensate and the superfluid fractions. We show that quantum gravity minimizes the interaction force between bosons leading to the formation of ultradilute Bose condensates. Our results which can be readily probed in current experiments may offer a new attractive possibility to understand gravity in the framework of quantum mechanics.

cond-mat.quant-gas↗

arXiv2021

Binary Bose-Einstein condensates in a disordered time-dependent potential

We study the non-equilibrium evolution of binary Bose-Einstein condensates in the presence of weak random potential with a Gaussian correlation function using the time-dependent perturbation theory. We apply this theory to construct a closed set of equations that highlight the role of the spectacular interplay between the disorder and the interspecies interactions in the time evolution of the density induced by disorder in each component. It is found that this latter increases with time favoring localization of both species. The time scale at which the theory remains valid depends on the respective system parameters. We show analytically and numerically that such a system supports a steady state that periodically changing during its time propagation. The obtained dynamical corrections indicate that disorder may transform the system into a stationary out-of-equilibrium states. Understanding this time evolution is pivotal for the realization of Floquet condensates.

cond-mat.dis-nn↗

arXiv2021

Moving binary Bose-Einstein condensates in a weak random potential

We study the behavior of moving Bose-Bose mixtures in a weak disordered potential in the realm of the Bogoliubov-Huang-Meng theory. Corrections due to the quantum fluctuations, disorder effects and the relative motion of two fluids to the glassy fraction, the condensed depletion, the anomalous density, and the equation of state of each species are obtained analytically for small velocity. We show that the intriguing interplay of the relative motion and the disorder potential could not only change the stability condition, but destroy also the localization process in the two condensates preventing the formation of a Bose glass state. Unexpectedly, we find that the quantum fluctuations reduce with the velocity of the two fluids. The obtained theoretical predictions are checked by our numerical results.

cond-mat.dis-nn↗

arXiv2021

Many-body and temperature effects in two-dimensional quantum droplets in Bose-Bose mixtures

We study the equilibrium properties of self-bound droplets in two-dimensional Bose mixtures employing the time-dependent Hartree-Fock-Bogoliubov theory. This theory allows one to understand both the many-body and temperature effects beyond the Lee-Huang-Yang description. We calculate higher-order corrections to the excitations, the sound velocity, and the energy of the droplet. Our results for the ground-state energy are compared with the diffusion Monte Carlo data and good agreement is found. The behavior of the depletion and anomalous density of the droplet is also discussed. At finite temperature, we show that the droplet emerges at temperatures well below the Berezinskii-Kosterlitz-Thouless transition temperature. The critical temperature strongly depends on the interspecies interactions. Our study is extended to the finite size droplet by numerically solving the generalized finite-temperature Gross-Pitaevskii equation which is obtained self-consistently from our formalism in the framework of the local density approximation.

cond-mat.quant-gas↗

arXiv2021

Quantum self-bound droplets in Bose-Bose mixtures: Effects of higher-order quantum and thermal fluctuations

We systematically study the effects of higher-order quantum and thermal fluctuations on the stabilization of self-bound droplets in Bose mixtures employing the time-dependent Hartree-Fock-Bogoliubov theory. We calculate the ground-state energy, the droplet equilibrium density, the depletion and anomalous density of the droplets as well as the critical temperature as a function of the relevant parameters. Our findings are compared with previous analytical predictions and diffusion Monte Carlo simulations. We employ our theory together with the local density approximation for quantum and thermal fluctuations to obtain an extended finite-temperature Gross-Pitaevskii equation. The density profiles and breathing modes of the droplet are deeply examined in terms of the interaction strength and the temperature by numerically solving the developed generalized Gross-Pitaevskii equation.

cond-mat.quant-gas↗