Dynamics of ultracold Bose quantum gases and in particular of bright solitons (Orale)

We present a theoretical study of solitonlike solutions and their dynamics of ultracold superfluid Fermi gases trapped in a time-dependent three-dimensional (3D) harmonic potential with gain or loss. The 3D analytical solitonlike solutions are obtained without introducing any additional integrability constraints used elsewhere. The propagation of both bright- and dark-soliton-like solutions is investigated. We show that the amplitudes of dark-soliton-like solutions exhibit periodic oscillation, whereas those of the bright-soliton-like ones do not show such behavior. Moreover, we highlight that the oscillation periods of dark-soliton-like solutions predicted by our approach are matched very well with those observed in a recent experiment carried out by Yefsah et al. [T. Yefsah, A. T. Sommer, M. J. H. Ku, L. W. Cheuk, W. Ji, W. S. Bakr, and M. W. Zwierlein, Nature (London) 499, 426 (2013)NATUAS0028-083610.1038/nature12338] in both Bose-Einstein condensation and unitarity regimes.We present a theoretical study of solitonlike solutions and their dynamics of ultracold superfluid Fermi gases trapped in a time-dependent three-dimensional (3D) harmonic potential with gain or loss. The 3D analytical solitonlike solutions are obtained without introducing any additional integrability constraints used elsewhere. The propagation of both bright- and dark-soliton-like solutions is investigated. We show that the amplitudes of dark-soliton-like solutions exhibit periodic oscillation, whereas those of the bright-soliton-like ones do not show such behavior. Moreover, we highlight that the oscillation periods of dark-soliton-like solutions predicted by our approach are matched very well with those observed in a recent experiment carried out by Yefsah et al. [T. Yefsah, A. T. Sommer, M. J. H. Ku, L. W. Cheuk, W. Ji, W. S. Bakr, and M. W. Zwierlein, Nature (London) 499, 426 (2013)NATUAS0028-083610.1038/nature12338] in both Bose-Einstein condensation and unitarity regimes.

Physical Review ESep 16, 20150 citations

Bright solitons in Bose-Einstein condensates

Josselin C. Garnier, F. Kh. Abdullaev

Jan 1, 20081 citation

Two-Dimensional Bright Solitons in Dipolar Bose-Einstein Condensates

P. Pedri, Luis Santos

We analyze the physics of bright solitons in 2D dipolar Bose-Einstein condensates. These solitons, which are not possible in short-range interacting gases, constitute the first realistic proposal of fully mobile stable 2D solitons in ultracold gases. In particular, we discuss the necessary conditions for the existence of stable 2D bright solitary waves by means of a 3D analysis of the lowest-lying excitations. We show that the anisotropy of the dipolar potential is crucial, since sufficiently large dipolar interactions can destabilize the 2D soliton. Additionally, we study the scattering of solitary waves, which, contrary to the contact-interacting case, is inelastic and could lead to fusion of the waves. Finally, the experimental possibilities for observability are discussed.We analyze the physics of bright solitons in 2D dipolar Bose-Einstein condensates. These solitons, which are not possible in short-range interacting gases, constitute the first realistic proposal of fully mobile stable 2D solitons in ultracold gases. In particular, we discuss the necessary conditions for the existence of stable 2D bright solitary waves by means of a 3D analysis of the lowest-lying excitations. We show that the anisotropy of the dipolar potential is crucial, since sufficiently large dipolar interactions can destabilize the 2D soliton. Additionally, we study the scattering of solitary waves, which, contrary to the contact-interacting case, is inelastic and could lead to fusion of the waves. Finally, the experimental possibilities for observability are discussed.

arXiv:cond-mat/0503019Physical Review LettersNov 10, 2005369 citations

p -wave stabilization of three-dimensional Bose-Fermi solitons

Nicholas G. Parker, David A. Smith

We explore bright soliton solutions of ultracold Bose-Fermi gases, showing that the presence of $p$ -wave interactions can remove the usual collapse instability and support stable soliton solutions that are global energy minima. A variational model that incorporates the relevant $s$ - and $p$ -wave interactions in the system is established analytically and solved to probe the dependencies of the soliton stationary states on key experimental parameters. Under attractive $s$ -wave interactions, bright solitons exist only as metastable states susceptible to collapse. Remarkably, the presence of repulsive $p$ -wave interactions alleviates this collapse instability. This dramatically widens the range of experimentally achievable soliton solutions and indicates greatly enhanced robustness. While we focus specifically on the boson-fermion pairing of ${}^{87}$ Rb and ${}^{40}$ K, the stabilization inferred by repulsive $p$ -wave interactions should apply to the wider remit of ultracold Bose-Fermi mixtures.We explore bright soliton solutions of ultracold Bose-Fermi gases, showing that the presence of $p$-wave interactions can remove the usual collapse instability and support stable soliton solutions that are global energy minima. A variational model that incorporates the relevant $s$- and $p$-wave interactions in the system is established analytically and solved to probe the dependencies of the soliton stationary states on key experimental parameters. Under attractive $s$-wave interactions, bright solitons exist only as metastable states susceptible to collapse. Remarkably, the presence of repulsive $p$-wave interactions alleviates this collapse instability. This dramatically widens the range of experimentally achievable soliton solutions and indicates greatly enhanced robustness. While we focus specifically on the boson-fermion pairing of ${}^{87}$Rb and ${}^{40}$K, the stabilization inferred by repulsive $p$-wave interactions should apply to the wider remit of ultracold Bose-Fermi mixtures.

arXiv:1108.3453Physical Review AJan 3, 20127 citations

Bright Solitons in Bose-Einstein Condensates: Theory

F. Kh. Abdullaev, Josselin C. Garnier

Springer eBooksDec 29, 20077 citations

We explore bright soliton solutions of ultracold Bose-Fermi gases, showing that the presence of

p

-wave interactions can remove the usual collapse instability and support stable soliton solutions that are global energy minima. A variational model that incorporates the relevant

s

- and

p

-wave interactions in the system is established analytically and solved to probe the dependencies of the soliton stationary states on key experimental parameters. Under attractive

s

-wave interactions, bright solitons exist only as metastable states susceptible to collapse. Remarkably, the presence of repulsive

p

-wave interactions alleviates this collapse instability. This dramatically widens the range of experimentally achievable soliton solutions and indicates greatly enhanced robustness. While we focus specifically on the boson-fermion pairing of

{}^{87}

Rb and

{}^{40}

K, the stabilization inferred by repulsive

p

-wave interactions should apply to the wider remit of ultracold Bose-Fermi mixtures.