Spontaneous coherence and collective modes in double-layer quantum-dot systems

We study the ground state and collective excitations of parabolically confined double-layer quantum-dot systems in a strong magnetic field. We identify parameter regimes where electrons form maximum density droplet states, quantum-dot analogs of the incompressible states of the bulk integer quantum Hall effect. In these regimes the Hartree-Fock approximation and the time-dependent Hartree-Fock approximations can be used to describe the ground state and collective excitations, respectively. We comment on the relationship between edge excitations of dots and edge magnetoplasmon excitations of bulk double-layer systems. © 1996 The American Physical Society.