THE COULOMB-BLOCKADE IN COUPLED QUANTUM DOTS

Individual quantum dots are often referred to as ''artificial atoms.'' Two tunnel-coupled quantum dots can be considered an ''artificial mol ecule.'' Low-temperature measurements were made on a series double qua ntum dot with adjustable interdot tunnel conductance that was fabricat ed in a gallium arsenide-aluminum gallium arsenide heterostructure, Th e Coulomb blockade was used to determine the ground-state charge confi guration within the ''molecule'' as a function of the total charge on the double dot and the interdot polarization induced by electrostatic gates. As the tunnel conductance between the two dots is increased fro m near zero to 2e (2)/h (where e is the electron charge and h is Planc k's constant), the measured conductance peaks of the double dot exhibi t pronounced changes in agreement with many-body theory.