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.
ASJC Scopus subject areas
- Physics and Astronomy(all)