Spontaneous Symmetry Breaking in Single and Molecular Quantum Dots
Classes of spontaneous symmetry breaking at zero and low magnetic fields in single quantum dots (QD{close_quote}s) and quantum dot molecules (QDM{close_quote}s) are discussed in relation to the ratio R{sub W} between the interelectron Coulomb repulsion and the harmonic confinement, using spin-and-space unrestricted Hartree-Fock calculations. These include Wigner crystallization for R{sub W}{gt}1 , and formation of noncrystallized electron puddles localized on the individual dots in QDM{close_quote}s, as well as spin-density waves in single QD{close_quote}s, for R{sub W}{lt}1 . {copyright} {ital 1999} {ital The American Physical Society}