Coulomb crystallites from harmonically confined charged bosons in two dimensions

A. I. MESE; P. CAPUZZI; Z. AKDENIZ; S. E. OKAN; M. P. TOSI

JOURNAL OF PHYSICS CONDENSED MATTER

Año: 2008 vol. 20 p. 335222 - 3352226

0953-8984

We exploit rotational-symmetry breaking in the one-body density to examine the formation ofstructures in systems of N strongly coupled charged bosons with logarithmic repulsions insideisotropic two-dimensional harmonic traps, with N in the range from 2 to 7. The results serve asa map for ordered arrangements of vortices in a trapped Bose–Einstein condensate. Two typesof N -body wavefunctions are assumed: (i) a permanent WM of N identical Gaussian orbitalscentred at variationally determined sites, and (ii) a permanent SM  of N orthogonal orbitalsbuilt from harmonic-oscillator energy eigenstates. With increasing coupling strength, thebosons in the WM orbitals localize into polygonal-ringlike crystalline patterns (‘Wignermolecules’), whereas the wavefunctions SM describe low energy excited states containingdelocalized bosons as in supersolid crystallites (‘supermolecules’). For N = 2 at strongcoupling both states describe a Wigner dimer.