Probing by transport the single-particle energy spectrum up to high energy of one quantum dot with the ground state of an adjacent weakly coupled quantum dot

We investigate single‐electron resonant tunneling through gated vertical quantum dot molecules for which the tunnel coupling between the two dots is weak to examine magnetic field induced two‐ and three‐level crossings in the single‐particle energy spectrum of the constituent dots. We consider two devices. Device I with almost circular dots is close to ideal, i.e., the dot spectrum is like the Fock–Darwin spectrum with expected level crossings. Device II with elliptically deformed dots seems close to ideal too, i.e., the dot spectrum is overall like the elliptical parabolic dot spectrum, except at many of the level crossings, where unexpected anti‐crossing behavior is observed between two or more approaching levels. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)