| 1. |
- Kavoulakis, Georgios, et al.
(författare)
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Rapidly rotating Bose-Einstein condensates in anharmonic potentials
- 2003
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Rapidly rotating Bose-Einstein condensates confined in anharmonic traps can exhibit a rich variety of vortex phases, including a vortex lattice, a vortex lattice with a hole, and a giant vortex. Using an augmented Thomas - Fermi variational approach to determine the ground state of the condensate in the rotating frame - valid for sufficiently strongly interacting condensates - we determine the transitions between these three phases for a quadratic- plus- quartic confining potential. Combining the present results with previous numerical simulations of small rotating condensates in such anharmonic potentials, we delineate the general structure of the zero-temperature phase diagram.
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| 2. |
- Wetzler, R, et al.
(författare)
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Inhomogeneous charging and screening effects in semiconductor quantum dot arrays
- 2004
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 6, s. 1-81
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Tidskriftsartikel (refereegranskat)abstract
- The electronic properties of quantum dot (QD) arrays are strongly influenced by the Coulomb interaction of electrons within the dot as well as with those in neighbouring dots. In this paper, we investigate this behaviour taking into account screening by a free electron gas in the vicinity of the QDs. We find pronounced effects for standard capacitance - voltage ( CV) measurements of QD structures embedded in a pn-diode. In particular, we show that the three-dimensional nature of the problem is crucial for devices with low dot-density, whereas the self-consistency between electron depletion in the bulk layer and dot occupation is important for high dot-densities. The Coulomb interaction between the dots induces a broadening of the peaks in the CV characteristic which is comparable with the effect of disordered QD arrays, where we considered realistic size and position fluctuations obtained by a kinetic Monte Carlo simulation.
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| 3. |
- Blom, Martin, et al.
(författare)
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Unity of CP and T violation in neutrino oscillations
- 2004
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 6, s. 130-
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Tidskriftsartikel (refereegranskat)abstract
- In a previous work, a simultaneous P-CP[P] and P-T [P] biprobability plot was proposed as a useful tool for a unified graphical description of CP and T violation in neutrino oscillations. The diamond-shaped structure of the plot is understood as a consequence of the approximate CP-CP and T-CP relations obeyed by the oscillation probabilities. In this paper, we take a step forward towards a deeper understanding of the unified graphical representation by showing that these two relations are identical in their content, suggesting a truly unifying view of CP and T violation in neutrino oscillations. We suspect that the unity reflects the underlying CPT theorem. We also present a calculation of corrections to the CP-CP and the T-CP relations to leading order in Deltam(21)(2)/Deltam(31)(2) and s(13)(2).
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| 4. |
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