Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0810.4207 · Physical Review A

Localized matter-wave patterns with attractive interaction in rotating potentials

Hidetsugu Sakaguchi, Boris A. Malomed

Published Dec 8, 2008• 21 citations
arXivHTMLPDF

Abstract

We consider a two-dimensional (2D) model of a rotating attractive Bose-Einstein condensate (BEC), trapped in an external potential. First, a harmonic potential with the critical strength is considered, which generates quasisolitons at the lowest Landau level (LLL). We describe a family of the LLL quasisolitons using both numerical method and a variational approximation (VA), which are in good agreement with each other. We demonstrate that kicking the LLL mode or applying a ramp potential sets it in the Larmor (cyclotron) motion that can also be accurately modeled by the VA. Collisions between two such moving modes may be elastic or inelastic depending on their total norm. If an additional confining potential is applied along with the ramp, it creates a stationary edge state. Applying a kick to the edge state in the direction of the ramp gives rise to a skipping motion in the perpendicular direction. These regimes may be interpreted as the Hall effect for the quasisolitons. Next, we consider the condensate trapped in an axisymmetric quartic potential. Three species of localized states and their stability regions are identified, viz., vortices with arbitrary topological charge $m$, ``crescents'' (mixed-vorticity states), and strongly localized center-of-mass (c.m.) states, alias quasisolitons, shifted off the rotation pivot. These results are similar to those reported before for the model with a combined quadratic-quartic trap. Stable pairs of c.m. states set at diametrically opposite points are found, too. We present a VA which provides for an accurate description of vortices with all values of $m$, and of the c.m. states. We also demonstrate that kicking them in the azimuthal direction sets the quasisolitons in epitrochoidal motion (which is also accurately predicted by the VA), collisions between them being elastic.

DOI
10.1103/physreva.78.063606

Related papers

Stabilizing single- and two-color vortex beams in quadratic media by a trapping potential

Hidetsugu Sakaguchi, Boris A. Malomed

We consider two-dimensional (2D) localized modes in the second-harmonic-generating (χ(2)) system with the harmonic-oscillator (HO) trapping potential. In addition to its realization in optics, the system describes the mean-field dynamics of mixed atomic-molecular Bose–Einstein condensates (BECs). The existence and stability of various modes is determined by their total power, N, topological charge, m/2 [m is the intrinsic vorticity of the second-harmonic (SH) field], and χ(2) mismatch, q. The analysis is carried out in a numerical form and, in parallel, by means of the variational approximation (VA), which produces results that agree well with numerical findings. Below a certain power threshold, N≤Nc(m)(q), all trapped modes are of the single-color type, represented by the SH component only, while the fundamental frequency (FF) one is absent. In contrast with the usual situation, where such modes are always unstable, we demonstrate that they are stable, for m=0, 1, 2 (the mode with m=1 may be formally considered as a semivortex with topological charge m/2=1/2), at N≤Nc(m)(q), and unstable above this threshold. On the other hand, Nc(m)(q)≡0 at q≥qmax (in our notation, qmax=1); hence the single-color modes are unstable in the latter case. At N=Nc(m), the modes with m=0 and m=2 undergo a pitchfork bifurcation, which gives rise to two-color states, which remain completely stable for m=0. The two-color vortices with m=2 (topological charge 1) have an upper stability border, N=Nc2(q). Above the border, they exhibit periodic splittings and recombinations, while keeping their vorticity. The semivortex does not bifurcate; at N=Nc(m=1), it exhibits quasi-chaotic oscillations and a rotating “groove” resembling a screw-edge dislocation induced by the semi-integer vorticity.

arXiv:1208.4191•Journal of the Optical Society of America B•Sep 13, 2012•22 citations

Two-dimensional matter-wave solitons in rotating optical lattices

Hidetsugu Sakaguchi, Boris A. Malomed

We construct soliton solutions for a self-attractive Bose-Einstein condensate trapped in a rotating optical lattice. The rotation pivot is set at a local maximum of the lattice potential. We demonstrate that fully localized stable solitons, containing $N\ensuremath{\sim}10,000$ atoms, may be supported by the lattice, rotating along with it, if the angular velocity $\ensuremath{\omega}$ is taken below a critical value ${\ensuremath{\omega}}_{c}$ (which is $\ensuremath{\lesssim}10\phantom{\rule{0.3em}{0ex}}\mathrm{kHz}$). A monotonously increasing dependence of ${\ensuremath{\omega}}_{c}$ on $N$ is found. In the regime of rapid rotation, the lattice potential is nearly tantamount to the axisymmetric Bessel potential, with a maximum at the center. The latter potential supports fundamental ring-shaped solitons, and also dipole states, which have a bipolar form of two adjacent ring solitons with opposite signs. Stability regions are found for both species (which is the first example of stable azimuthally uniform solitons in a self-focusing model with a radial potential). Unstable solitons of these types evolve into strongly localized nonrotating states. At smaller $\ensuremath{\omega}$, they start to drift slowly, following the rotating lattice. The second critical value, $\ensuremath{\omega}={\ensuremath{\omega}}_{c}^{(2)}$, is found, below which the drifting solitons are destroyed. The rotating lattice supports no stable states in the interval of ${\ensuremath{\omega}}_{c}<\ensuremath{\omega}<{\ensuremath{\omega}}_{c}^{(2)}$.

Physical Review A•Jan 10, 2007•27 citations

Solitons in Bose-Einstein condensates with attractive self-interaction on a Möbius strip

Huan-Bo Luo, Guilong Li, Fu-Quan Dou +4 more

We study the matter-wave solitons in Bose-Einstein condensate (BEC) trapped on a M\"obius st rip (MS), based on the respective Gross-Pitaevskii (GP) equation with the mean-field theory. In the linear regime, vortex states are characterized by quantum numbers, $n$ and $m$, corresponding to the transverse and circumferential directions, with the phase structure determined by the winding number (WN) $m$. Odd and even values of $n$ must associate, respectively, with integer and half-integer values of $m$, the latter ones requiring two cycles of motion around MS for returning to the initial phase. Using variational and numerical methods, we solve the GP equation with the attractive nonlinearity, producing a family of ground-state (GS) solitons for values of the norm below the critical one, above which the collapse sets in. Vortex solitons with $n=1,m=1$ and $n=2,m=1/2$ are obtained in a numerical form. The vortex solitons with $n=1,m=1$ are almost uniformly distributed in the azimuthal direction, while ones with $n=2,m=1/2$ form localized states. The Vakhitov-Kolokolov criterion and linear-stability analysis for the GS soliton solutions and vortices with $n=1,m=1$ demonstrates that they are completely stable, while the localized states with $n=2,m=1/2$ are completely unstable. Finally, the motion of solitons on the MS and the collision of two solitons are discussed.

arXiv:2502.09087•Physical Review A•Feb 21, 2025•6 citations

Lowest-Landau-level vortex structure of a Bose-Einstein condensate rotating in a harmonic plus quartic trap

Xavier Blanc, Nicolas Rougerie

We investigate the vortex patterns appearing in a two-dimensional annular Bose-Einstein condensate rotating in a quadratic plus quartic confining potential. We show that in the limit of small anharmonicity the Gross-Pitaevskii energy can be minimized among the lowest-Landau-level wave functions and use this particular form to obtain theoretical results in the spirit of Aftalion et al. [Phys. Rev. A 73, 011601(R) (2006)]. In particular, we show that the vortex pattern is infinite but not uniform. We also compute numerically the complete vortex structure: It is an Abrikosov lattice strongly distorted near the edges of the condensate with multiply quantized vortices appearing at the center of the trap.

arXiv:0801.3571•Physical Review A•May 29, 2008•23 citations

Matter-wave solitons in radially periodic potentials

Bakhtiyor B. Baizakov, Boris A. Malomed, Mario Salerno

We investigate two-dimensional (2D) states in Bose-Einstein condensates with self-attraction or self-repulsion, trapped in an axially symmetric optical-lattice potential periodic along the radius. The states trapped both in the central potential well and in remote circular troughs are studied. In the repulsive mode, a new soliton species is found, in the form of radial gap solitons. The latter solitons are completely stable if they carry zero vorticity (l=0) , while with l not equal 0 they develop a weak azimuthal modulation, which makes them rotating patterns, that persist indefinitely long. In addition, annular gap solitons may support stable azimuthal dark-soliton pairs on their crests. In remote troughs of the attractive model, stable localized states may assume a ringlike shape with weak azimuthal modulation, or shrink into solitons strongly localized in the azimuthal direction, which is explained in the framework of an averaged 1D equation with the cyclic azimuthal coordinate. Numerical simulations of the attractive model also reveal stable necklacelike patterns, built of several strongly localized peaks. Dynamics of strongly localized solitons circulating in the troughs is studied too. While the solitons with sufficiently small velocities are completely stable, fast solitons gradually decay, due to the leakage of matter into the adjacent trough, under the action of the centrifugal force. Investigation of head-on collisions between strongly localized solitons traveling in circular troughs shows that collisions between in-phase solitons in a common trough lead to collapse, while pi-out-of-phase solitons bounce many times, but eventually merge into a single one, without collapsing. In-phase solitons colliding in adjacent circular troughs also tend to merge into a single soliton.

arXiv:cond-mat/0605283•Physical Review E•Dec 29, 2006•89 citations

Vortex formation in a fast rotating Bose-Einstein condensate

Tarun Kanti Ghosh

We study rotational motion of an interacting atomic Bose-Einstein condensate confined in a quadratic-plus-quartic potential. We calculate the lowest energy surface mode frequency and show that a symmetric trapped (harmonic and quartic) Bose-Einstein condensate breaks the rotational symmetry of the Hamiltonian when rotational frequency is greater than one-half of the lowest energy surface mode frequency. We argue that the formation of a vortex is not possible in a non-interacting as well as in an attractive Bose-Einstein condensate confined in a harmonic trap due to the absence of the spontaneous shape deformation, but it can occur which leads to the vortex formation if we add an additional quartic potential. Moreover, the spontaneous shape deformation and consequently the formation of a vortex in an attractive system depends on the strengths of the two-body interaction and the quartic potential.

arXiv:cond-mat/0306563•Jun 23, 2003•0 citations
We consider a two-dimensional (2D) model of a rotating attractive Bose-Einstein condensate (BEC), trapped in an external potential. First, a harmonic potential with the critical strength is considered, which generates quasisolitons at the lowest Landau level (LLL). We describe a family of the LLL quasisolitons using both numerical method and a variational approximation (VA), which are in good agreement with each other. We demonstrate that kicking the LLL mode or applying a ramp potential sets it in the Larmor (cyclotron) motion that can also be accurately modeled by the VA. Collisions between two such moving modes may be elastic or inelastic depending on their total norm. If an additional confining potential is applied along with the ramp, it creates a stationary edge state. Applying a kick to the edge state in the direction of the ramp gives rise to a skipping motion in the perpendicular direction. These regimes may be interpreted as the Hall effect for the quasisolitons. Next, we consider the condensate trapped in an axisymmetric quartic potential. Three species of localized states and their stability regions are identified, viz., vortices with arbitrary topological charge mmm, ``crescents'' (mixed-vorticity states), and strongly localized center-of-mass (c.m.) states, alias quasisolitons, shifted off the rotation pivot. These results are similar to those reported before for the model with a combined quadratic-quartic trap. Stable pairs of c.m. states set at diametrically opposite points are found, too. We present a VA which provides for an accurate description of vortices with all values of mmm, and of the c.m. states. We also demonstrate that kicking them in the azimuthal direction sets the quasisolitons in epitrochoidal motion (which is also accurately predicted by the VA), collisions between them being elastic.
We consider two-dimensional (2D) localized modes in the second-harmonic-generating (χ(2)) system with the harmonic-oscillator (HO) trapping potential. In addition to its realization in optics, the system describes the mean-field dynamics of mixed atomic-molecular Bose–Einstein condensates (BECs). The existence and stability of various modes is determined by their total power, N, topological charge, m/2 [m is the intrinsic vorticity of the second-harmonic (SH) field], and χ(2) mismatch, q. The analysis is carried out in a numerical form and, in parallel, by means of the variational approximation (VA), which produces results that agree well with numerical findings. Below a certain power threshold, N≤Nc(m)(q), all trapped modes are of the single-color type, represented by the SH component only, while the fundamental frequency (FF) one is absent. In contrast with the usual situation, where such modes are always unstable, we demonstrate that they are stable, for m=0, 1, 2 (the mode with m=1 may be formally considered as a semivortex with topological charge m/2=1/2), at N≤Nc(m)(q), and unstable above this threshold. On the other hand, Nc(m)(q)≡0 at q≥qmax (in our notation, qmax=1); hence the single-color modes are unstable in the latter case. At N=Nc(m), the modes with m=0 and m=2 undergo a pitchfork bifurcation, which gives rise to two-color states, which remain completely stable for m=0. The two-color vortices with m=2 (topological charge 1) have an upper stability border, N=Nc2(q). Above the border, they exhibit periodic splittings and recombinations, while keeping their vorticity. The semivortex does not bifurcate; at N=Nc(m=1), it exhibits quasi-chaotic oscillations and a rotating “groove” resembling a screw-edge dislocation induced by the semi-integer vorticity.
We construct soliton solutions for a self-attractive Bose-Einstein condensate trapped in a rotating optical lattice. The rotation pivot is set at a local maximum of the lattice potential. We demonstrate that fully localized stable solitons, containing $N\ensuremath{\sim}10,000$ atoms, may be supported by the lattice, rotating along with it, if the angular velocity $\ensuremath{\omega}$ is taken below a critical value ${\ensuremath{\omega}}_{c}$ (which is $\ensuremath{\lesssim}10\phantom{\rule{0.3em}{0ex}}\mathrm{kHz}$). A monotonously increasing dependence of ${\ensuremath{\omega}}_{c}$ on NNN is found. In the regime of rapid rotation, the lattice potential is nearly tantamount to the axisymmetric Bessel potential, with a maximum at the center. The latter potential supports fundamental ring-shaped solitons, and also dipole states, which have a bipolar form of two adjacent ring solitons with opposite signs. Stability regions are found for both species (which is the first example of stable azimuthally uniform solitons in a self-focusing model with a radial potential). Unstable solitons of these types evolve into strongly localized nonrotating states. At smaller $\ensuremath{\omega}$, they start to drift slowly, following the rotating lattice. The second critical value, $\ensuremath{\omega}={\ensuremath{\omega}}_{c}^{(2)}$, is found, below which the drifting solitons are destroyed. The rotating lattice supports no stable states in the interval of ${\ensuremath{\omega}}_{c}<\ensuremath{\omega}<{\ensuremath{\omega}}_{c}^{(2)}$.
We study the matter-wave solitons in Bose-Einstein condensate (BEC) trapped on a M\"obius st rip (MS), based on the respective Gross-Pitaevskii (GP) equation with the mean-field theory. In the linear regime, vortex states are characterized by quantum numbers, nnn and mmm, corresponding to the transverse and circumferential directions, with the phase structure determined by the winding number (WN) mmm. Odd and even values of nnn must associate, respectively, with integer and half-integer values of mmm, the latter ones requiring two cycles of motion around MS for returning to the initial phase. Using variational and numerical methods, we solve the GP equation with the attractive nonlinearity, producing a family of ground-state (GS) solitons for values of the norm below the critical one, above which the collapse sets in. Vortex solitons with n=1,m=1n=1,m=1n=1,m=1 and n=2,m=1/2n=2,m=1/2n=2,m=1/2 are obtained in a numerical form. The vortex solitons with n=1,m=1n=1,m=1n=1,m=1 are almost uniformly distributed in the azimuthal direction, while ones with n=2,m=1/2n=2,m=1/2n=2,m=1/2 form localized states. The Vakhitov-Kolokolov criterion and linear-stability analysis for the GS soliton solutions and vortices with n=1,m=1n=1,m=1n=1,m=1 demonstrates that they are completely stable, while the localized states with n=2,m=1/2n=2,m=1/2n=2,m=1/2 are completely unstable. Finally, the motion of solitons on the MS and the collision of two solitons are discussed.
We investigate the vortex patterns appearing in a two-dimensional annular Bose-Einstein condensate rotating in a quadratic plus quartic confining potential. We show that in the limit of small anharmonicity the Gross-Pitaevskii energy can be minimized among the lowest-Landau-level wave functions and use this particular form to obtain theoretical results in the spirit of Aftalion et al. [Phys. Rev. A 73, 011601(R) (2006)]. In particular, we show that the vortex pattern is infinite but not uniform. We also compute numerically the complete vortex structure: It is an Abrikosov lattice strongly distorted near the edges of the condensate with multiply quantized vortices appearing at the center of the trap.
We investigate two-dimensional (2D) states in Bose-Einstein condensates with self-attraction or self-repulsion, trapped in an axially symmetric optical-lattice potential periodic along the radius. The states trapped both in the central potential well and in remote circular troughs are studied. In the repulsive mode, a new soliton species is found, in the form of radial gap solitons. The latter solitons are completely stable if they carry zero vorticity (l=0) , while with l not equal 0 they develop a weak azimuthal modulation, which makes them rotating patterns, that persist indefinitely long. In addition, annular gap solitons may support stable azimuthal dark-soliton pairs on their crests. In remote troughs of the attractive model, stable localized states may assume a ringlike shape with weak azimuthal modulation, or shrink into solitons strongly localized in the azimuthal direction, which is explained in the framework of an averaged 1D equation with the cyclic azimuthal coordinate. Numerical simulations of the attractive model also reveal stable necklacelike patterns, built of several strongly localized peaks. Dynamics of strongly localized solitons circulating in the troughs is studied too. While the solitons with sufficiently small velocities are completely stable, fast solitons gradually decay, due to the leakage of matter into the adjacent trough, under the action of the centrifugal force. Investigation of head-on collisions between strongly localized solitons traveling in circular troughs shows that collisions between in-phase solitons in a common trough lead to collapse, while pi-out-of-phase solitons bounce many times, but eventually merge into a single one, without collapsing. In-phase solitons colliding in adjacent circular troughs also tend to merge into a single soliton.
We study rotational motion of an interacting atomic Bose-Einstein condensate confined in a quadratic-plus-quartic potential. We calculate the lowest energy surface mode frequency and show that a symmetric trapped (harmonic and quartic) Bose-Einstein condensate breaks the rotational symmetry of the Hamiltonian when rotational frequency is greater than one-half of the lowest energy surface mode frequency. We argue that the formation of a vortex is not possible in a non-interacting as well as in an attractive Bose-Einstein condensate confined in a harmonic trap due to the absence of the spontaneous shape deformation, but it can occur which leads to the vortex formation if we add an additional quartic potential. Moreover, the spontaneous shape deformation and consequently the formation of a vortex in an attractive system depends on the strengths of the two-body interaction and the quartic potential.