Ground state of a partially melted Wigner molecule
CEA, Service de Physique de l'Etat Condensé,
Centre d'Etudes de Saclay F-91191 Gif-sur-Yvette Cedex, France
2 Eötvös University, Departement of Physics of Complex Systems H-1117 Budapest, Pázmány Péter sétány 1/A, Hungary
Accepted: 14 March 2002
We consider three spinless fermions free to move on 2d square lattice with periodic boundary conditions and interacting via a U/r Coulomb repulsion. When the Coulomb energy to kinetic energy ratio rs is large, a rigid Wigner molecule is formed. As rs decreases, we show that melting proceeds via an intermediate regime where a floppy two-particle molecule coexists with a partially delocalized particle. A simple ansatz is given to describe the ground state of this mesoscopic solid-liquid regime.
PACS: 71.10.-w – Theories and models of many-electron systems / 71.27.+a – Strongly correlated electron systems; heavy fermions / 73.20.Qt – Electron solids
© EDP Sciences, 2002