A model for classical impurities moving in Bose-Einstein Condensate (BEC) is proposed in the framework of quantum field theory and is solved within the Bogoliubov approximation at zero temperature. Several formulae are obtained for physical quantities such as the occupation number, the dissipation, the free energy, and the depletion. To illustrate this model two examples are studied; an impurity moving with i) a constant velocity and ii) a constant acceleration. Landau's criterion for energy dissipation accompanying the motion of impurities due to creation of quasi-particles in a superfluid, which was proposed on the basis of purely phenomenological argument, is obtained in the frame work of an exact quantum mechanical model.A model for classical impurities moving in Bose-Einstein Condensate (BEC) is proposed in the framework of quantum field theory and is solved within the Bogoliubov approximation at zero temperature. Several formulae are obtained for physical quantities such as the occupation number, the dissipation, the free energy, and the depletion. To illustrate this model two examples are studied; an impurity moving with i) a constant velocity and ii) a constant acceleration. Landau's criterion for energy dissipation accompanying the motion of impurities due to creation of quasi-particles in a superfluid, which was proposed on the basis of purely phenomenological argument, is obtained in the frame work of an exact quantum mechanical model.

arXiv:cond-mat/0407714Jul 28, 20040 citations

Universality of an impurity in a Bose-Einstein condensate

Meera M. Parish

Bulletin of the American Physical SocietyMay 31, 20180 citations

Dynamics of an impurity in a finite temperature Bose-Einstein condensate

Jonas Rønning, Audun Skaugen, Emilio Hernández-Garcı́a +2 more

Bulletin of the American Physical SocietyMar 19, 20210 citations

Dynamics of bright matter-wave solitons in inhomogeneous cigar-type Bose-Einstein condensate

F. Kh. Abdullaev, A. Gammal, Lauro Tomio

We discuss the possible observation of a new type of standing nonlinear atomic matter wave in the condensate: the nonlinear impurity mode. It is investigated dynamical effects of a bright soliton in Bose-Einstein-condensed (BEC) systems with local space variations of the two-body atomic scattering length. A rich dynamics is observed in the interaction between the soliton and an inhomogeneity. Processes as trapping, reflection and transmission of the bright matter soliton due to the impurity are studied considering an analytical time-dependent variational approach and also by full numerical simulation. A condition is obtained for the collapse of the bright solitary wave in the quasi-one-dimensional BEC with attractive local inhomogeneity.We discuss the possible observation of a new type of standing nonlinear atomic matter wave in the condensate: the nonlinear impurity mode. It is investigated dynamical effects of a bright soliton in Bose-Einstein-condensed (BEC) systems with local space variations of the two-body atomic scattering length. A rich dynamics is observed in the interaction between the soliton and an inhomogeneity. Processes as trapping, reflection and transmission of the bright matter soliton due to the impurity are studied considering an analytical time-dependent variational approach and also by full numerical simulation. A condition is obtained for the collapse of the bright solitary wave in the quasi-one-dimensional BEC with attractive local inhomogeneity.

arXiv:cond-mat/0210613Oct 28, 20023 citations

Quantum dynamics of impurities in a Bose–Einstein condensate

Javed Akram

arXiv:2211.00403Applied Physics BJul 12, 20212 citations

Two-component Bose-Einstein condensates in D -dimensional optical lattices

Jianjun Wang, Ai‐Xia Zhang, Kezhi Zhang +2 more

The impurity-induced self-trapping and stable moving soliton and breather of two-component Bose-Einstein condensates (BEC's) in deep $D$ -dimensional optical lattices are discussed both analytically and numerically. Under the tight-binding approximation and within a time-dependent variational approach, analytical criteria for occurrences of a self-trapping, moving soliton and breather in the system are obtained. The analytical results are confirmed by direct numerical simulation. It is shown that the dynamics of the condensates can be modified significantly by a minor admixture of an impurity (the second component). The diffusion state of the single-component BEC will transit to the self-trapped state due to the minor admixture of an impurity, even if the two condensates are only with marginal spatial overlap. Furthermore, we find that, in certain conditions, a stable moving soliton can exist in high-dimensional lattices for the two-component BEC's, which is very different from the single-component BEC (where a moving soliton cannot be stabilized in high-dimensional lattices). On the other hand, the impurity can play a crucial role in causing important coherence-decoherence and localization-delocalization phase transitions.The impurity-induced self-trapping and stable moving soliton and breather of two-component Bose-Einstein condensates (BEC's) in deep $D$-dimensional optical lattices are discussed both analytically and numerically. Under the tight-binding approximation and within a time-dependent variational approach, analytical criteria for occurrences of a self-trapping, moving soliton and breather in the system are obtained. The analytical results are confirmed by direct numerical simulation. It is shown that the dynamics of the condensates can be modified significantly by a minor admixture of an impurity (the second component). The diffusion state of the single-component BEC will transit to the self-trapped state due to the minor admixture of an impurity, even if the two condensates are only with marginal spatial overlap. Furthermore, we find that, in certain conditions, a stable moving soliton can exist in high-dimensional lattices for the two-component BEC's, which is very different from the single-component BEC (where a moving soliton cannot be stabilized in high-dimensional lattices). On the other hand, the impurity can play a crucial role in causing important coherence-decoherence and localization-delocalization phase transitions.

Physical Review AMar 12, 20109 citations

The impurity-induced self-trapping and stable moving soliton and breather of two-component Bose-Einstein condensates (BEC's) in deep

D

-dimensional optical lattices are discussed both analytically and numerically. Under the tight-binding approximation and within a time-dependent variational approach, analytical criteria for occurrences of a self-trapping, moving soliton and breather in the system are obtained. The analytical results are confirmed by direct numerical simulation. It is shown that the dynamics of the condensates can be modified significantly by a minor admixture of an impurity (the second component). The diffusion state of the single-component BEC will transit to the self-trapped state due to the minor admixture of an impurity, even if the two condensates are only with marginal spatial overlap. Furthermore, we find that, in certain conditions, a stable moving soliton can exist in high-dimensional lattices for the two-component BEC's, which is very different from the single-component BEC (where a moving soliton cannot be stabilized in high-dimensional lattices). On the other hand, the impurity can play a crucial role in causing important coherence-decoherence and localization-delocalization phase transitions.