Density of condensate of a dilute Bose gas in improved Hartree-Fock approximation

Finite size effect on Bose-Einstein condensate mixtures in improved Hartree-Fock approximation

Using Cornwal-Jackiw-Tomboulis effective potential approach we found that at zero temperature, in improved Hartree-Fock approximation, the effective masses and order parameters of a two component Bose-Einstein condensates confined between two parallel plates strongly depend on the distance between two slabs. The Casimir force is also considered in this approximation and shown that this force differs from zero in limit of strong segregation.

The condensed fraction of a homogeneous dilute Bose gas within the improved Hartree-Fock approximation

Motivated by the recent experiment [R. Lopes et. al., Phys. Rev. Lett. 119, 190404 (2017)] with a homogeneous Bose gas, we investigate a homogeneous dilute Bose gas to calculate the quantum depletion density. By means of the Cornwall-Jackiw-Tomboulis effective action approach within an improved Hartree-Fock approximation, the condensed fraction is recovered in a simpler manner and compared with corresponding findings in experimental data. Additionally, higher-order terms are taken into account for several physical quantities, in particular for the chemical potential and free energy density.

Casimir effect in a dilute Bose gas in canonical ensemble within improved Hartree-Fock approximation

The Casimir effect in a dilute Bose gas confined between two planar walls is investigated in the canonical ensemble at zero temperature by means of Cornwall-Jackiw-Tomboulis effective action approach within the improved Hartree-Fock approximation. Our results show that: (i) the Casimir energy and the resulting Casimir force in the canonical ensemble remarkably differ from those in the grand canonical ensemble; (ii) when the distance between two planar walls increases, the Casimir energy and Casimir force decay in accordance with a half-integer power law in the canonical ensemble instead of an …

改进Hartree-Fock近似下双分量玻色-爱因斯坦凝聚体的转变温度

Transition temperature of a two-component Bose-Einstein condensates in improved Hartree-Fock approximation

本研究采用改进的Hartree-Fock近似和CJT有效作用量形式，计算了双分量玻色-爱因斯坦凝聚体的转变温度，并考虑了种内、种间相互作用及热涨落至领头阶的影响。

Quantum correlations in dipolar droplets: Time-dependent Hartree-Fock-Bogoliubov theory

We investigate the effects of quantum correlations on dipolar quantum droplets. To this end,we derive self-consistent time-dependent Hartree-Fock-Bogoliubov equations that fairly describe the dynamics of the order parameter, the normal, and anomalous quantum correlations of the droplet. We analyze the density profiles, the critical number of particles, the condensate depletion, and the pair correlation function. Our predictions are compared with very recent experimental and Quantum Monte-Carlo simulations results and excellent agreement is found.

Implicit ladder summation in the Hartree-Fock-Bogoliubov approach

The fully variational Hartree Fock Bogoliubov approach for bosons is studied in the limit of zero range forces in two- and three-dimensions. The equation of state obtained in two-dimensions is expressed in a parametric form. It is shown that the $Λ$ potential permits to perform an implicit summation of the ladder diagrams without leaving the variational scheme, restoring thus the consistency of this approximation.