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Vortex formation in quantum dots in high magnetic fields

H. Saarikoski·A. Harju·M. J. Puska·R. M. Nieminen
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Abstract

We study electronic structures of two-dimensional quantum dots in high magnetic fields using the density-functional theory (DFT) and the exact diagonalization (ED). With increasing magnetic field, beyond the formation of the totally spin-polarized maximum density droplet (MDD) state, the DFT gives the ground-state total angular momentum as a continuous function with well-defined plateaus. The plateaus agree well with the magic angular momenta of the ED calculation. By constructing a conditional wave function from the Kohn-Sham states we show that vortices enter the quantum dot one-by-one at the transition to the state with the adjacent magic angular momentum. Vortices are also observed outside the high-density region of the quantum dot. These findings are compared to the ED results and we report a significant agreement. We study also interpretations and limitations of the density functional approach in these calculations.

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H. Saarikoski, A. Harju, M. J. Puska, R. M. Nieminen. 2004-04-29. Vortex formation in quantum dots in high magnetic fields. https://doi.org/10.1016/j.physe.2004.08.070

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