Coulomb crystallites from harmonically confined charged bosons in two dimensions


Mese A. I. , Capuzzi P., Akdeniz Z., Okan S. E. , Tosi M. P.

JOURNAL OF PHYSICS-CONDENSED MATTER, cilt.20, 2008 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

We exploit rotational-symmetry breaking in the one-body density to examine the formation of structures in systems of N strongly coupled charged bosons with logarithmic repulsions inside isotropic two-dimensional harmonic traps, with N in the range from 2 to 7. The results serve as a map for ordered arrangements of vortices in a trapped Bose-Einstein condensate. Two types of N-body wavefunctions are assumed: (i) a permanent vertical bar psi(WM)> of N identical Gaussian orbitals centred at variationally determined sites, and (ii) a permanent vertical bar psi(SM)> of N orthogonal orbitals built from harmonic-oscillator energy eigenstates. With increasing coupling strength, the bosons in the vertical bar psi(WM)> orbitals localize into polygonal-ringlike crystalline patterns ('Wigner molecules'), whereas the wavefunctions vertical bar psi(SM)> describe low energy excited states containing delocalized bosons as in supersolid crystallites ('supermolecules'). For N = 2 at strong coupling both states describe a Wigner dimer.