Creffield, CharlesHáusler, WolfgangJefferson, John HSarkar, Sarben2023-06-202023-06-201999-04-151098-012110.1103/PhysRevB.59.10719https://hdl.handle.net/20.500.14352/59755©1999 The American Physical Society. C.E.C. is grateful for financial support from the Leverhulme Foundation and W.H. acknowledges support by the Deutsche Forschungsgemeinschaft through SFB 276. EU support from the TMR program is also gratefully acknowledged.The low-lying eigenstates of a system of two electrons confined within a two-dimensional quantum dot with a hard polygonal boundary are obtained by means of exact diagonalization. The transition from a weakly correlated charge distribution for small dots to a strongly correlated ‘‘Wigner molecule’’ for large dots is studied, and the behavior at the crossover is determined. In sufficiently large dots, a recently proposed mapping to an effective charge-spin model is investigated, and is found to produce the correct ordering of the energy levels and to give a good first approximation to the size of the level spacings. We conclude that this approach is a valuable method to obtain the low-energy spectrum of few-electron quantum dots.engjournal articlehttp://dx.doi.org/10.1103/PhysRevB.59.10719http://journals.aps.orgopen access538.9ModelQCDFísica de materialesFísica del estado sólido2211 Física del Estado Sólido