| 1. |
- Bargi, Sara, et al.
(author)
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Mixtures of Bose gases under rotation
- 2007
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In: Physical Review Letters. - 1079-7114. ; 98:13, s. 130403-130407
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Journal article (peer-reviewed)abstract
- We examine the rotational properties of a mixture of two Bose gases. Considering the limit of weak interactions between the atoms, we investigate the behavior of the system under a fixed angular momentum. We demonstrate a number of exact results in this many-body system.
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| 2. |
- Bargi, Sara, et al.
(author)
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Rotating Bose-Einstein condensates confined in an anharmonic potential
- 2006
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 73:3: 033613
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Journal article (peer-reviewed)abstract
- We consider bosonic atoms that rotate in an anharmonic trapping potential. Using numerical diagonalization of the Hamiltonian, we get evidence for various phases of the gas for different values of the coupling between the atoms and of the rotational frequency of the trap. These include vortex excitation of single and multiple quantization, the phase of center-of-mass excitation, and the unstable phase.
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| 3. |
- Cremon, Jonas, et al.
(author)
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Rotational properties of a mixture of two Bose gases
- 2008
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In: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 10
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Journal article (peer-reviewed)abstract
- A rotating, two-component Bose-Einstein condensate is shown to exhibit vortices of multiple quantization, which are possible due to the interatomic interactions between the two species. Also, persistent currents are absent in this system. Finally, the order parameter has a very simple structure for a range of angular momenta.
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| 4. |
- Jackson, A. D., et al.
(author)
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Bose-Einstein-condensed atoms in toroidal traps
- 2006
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 74:6
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Journal article (peer-reviewed)abstract
- We consider Bose-Einstein-condensed atoms confined in a toroidal trap. Under conditions of one-dimensional behavior, the density distribution of the atoms may be exponentially localized or delocalized, even for very small variations in the trapping potential along the torus. For similar reasons, small irregularities of the trap may also have a very pronounced effect on the density of the cloud. The excitation spectrum is also affected by the presence of some spatially varying potential and/or irregularities in the trap.
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| 5. |
- Jackson, A D, et al.
(author)
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Phase diagram of a rotating Bose-Einstein condensate with anharmonic confinement
- 2004
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In: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 69:5, s. 053619-
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Journal article (peer-reviewed)abstract
- We examine the phase diagram of an effectively repulsive Bose-Einstein condensate of atoms that rotates in a quadratic-plus-quartic potential. With use of a variational method we identify the three possible phases of the system as a function of the rotational frequency of the trap and of the coupling constant. The derived phase diagram is shown to be universal and partly exact in the limit of weak interactions and small anharmonicity. The variational results are found to be consistent with numerical solutions of the Gross-Pitaevskii equation.
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| 6. |
- Jackson, A D, et al.
(author)
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Stability of the solutions of the Gross-Pitaevskii equation
- 2005
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In: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 72:5, s. 053617-
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Journal article (peer-reviewed)abstract
- We examine the static and dynamic stability of the solutions of the Gross-Pitaevskii equation and demonstrate the intimate connection between them. All salient features related to dynamic stability are reflected systematically in static properties. We find, for example, the obvious result that static stability always implies dynamic stability and present a simple explanation of the fact that dynamic stability can exist even in the presence of static instability.
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| 7. |
- Jackson, AD, et al.
(author)
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Lieb mode in a quasi-one-dimensional Bose-Einstein condensate of atoms
- 2002
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In: Physical Review Letters. - 1079-7114. ; 89:7
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Journal article (peer-reviewed)abstract
- We calculate the dispersion relation associated with a solitary wave in a quasi-one-dimensional Bose-Einstein condensate of atoms confined in a harmonic, cylindrical trap in the limit of weak and strong interactions. In both cases, the dispersion relation is linear for long-wavelength excitations and terminates at the point where the group velocity vanishes. We also calculate the dispersion relation of sound waves in both limits of weak and strong coupling.
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| 8. |
- Jackson, AD, et al.
(author)
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Propagation of exciton pulses in semiconductors
- 2002
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In: Europhysics Letters. - : IOP Publishing. - 0295-5075 .- 1286-4854. ; 59:6, s. 807-813
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Journal article (peer-reviewed)abstract
- Using toy model, we examine the propagation of excitons in Cu2O, which form localized pulses under certain experimental conditions. The formation of these waves is attributed to the effect of dispersion, non-linearity and the coupling of the excitons to phonons, which acts as dissipative mechanism.
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| 9. |
- Jackson, AD, et al.
(author)
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Vortices and hysteresis in a rotating Bose-Einstein condensate with anharmonic confinement
- 2004
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 70:2
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Journal article (peer-reviewed)abstract
- We examine an effectively repulsive Bose-Einstein condensate of atoms that rotates in a quadratic-plus-quartic trapping potential. We investigate the phase diagram of the system as a function of the angular frequency of rotation and of the coupling constant, demonstrating that there are phase transitions between multiply and singly quantized vortex states. We also show that states of different circulation can be metastable and, as a result, the gas can exhibit hysteresis as the angular frequency of rotation of the trap is varied. The simplicity of the picture that emerges for small coupling strengths suggests that this system may be attractive for studies of phase transitions.
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| 10. |
- Kailasvuori, J M, et al.
(author)
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Bose-Einstein condensates in strong electric fields: Effective gauge potentials and rotating states
- 2002
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 66:5
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Journal article (peer-reviewed)abstract
- Magnetically trapped atoms in Bose-Einstein condensates are spin polarized. Since the magnetic field is inhomogeneous, the atoms acquire Berry phases of the Aharonov-Bohm type during adiabatic motion. In the presence of an electric field, there is an additional Aharonov-Casher effect. Taking into account the limitations on the strength of the electric fields due to the polarizability of the atoms, we investigate the extent to which these effects can be used to induce rotation in a Bose-Einstein condensate.
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