Single-electron spectroscopy in a coupled triple-dot system: Role of interdot electron-electron interactions

We report on low-temperature single electron tunneling measurements of a coupled triple-dot system with tunable gate fabricated on a silicon-on-insulator structure. Conductance peak positions have been measured as a function of the interdot tunneling constant. We observe one peak at small values of the tunneling constant, and, as the tunneling constant increases, we find that this peak splits into several peaks with uneven spacings. This observed behavior of the conductance peak positions has been modeled by a three-site extended Hubbard model with interdot electron-electron interactions.