Quantum Dots - artificial atoms constructed from semiconductors are expected to provide the basis for the future electronics. These artifical atoms represent the foundation of some of the most promising nanotechnologies - the single-electron transistor, where the charge of the quantum dot produces the non-linearity, and the spintronics - the control of charge transport through manipulation of the spins of the electrons in the dot.
Due to the extreme electron confinement in the nano-scale quantum dots, and the strong fluctuations of the electron density in a dot with only a few electrons, the simple mean-field description of the electron-electron interactions, brakes down.
Charge density fluctuations also lead to the violation of the Hund's rule and dramatically change the spin states occupation in the nano-scale quantum dots. Understanding of these fundamental effects and the development of the methods of their quantitative description is therefore critrical to the successful development of the future nanotechnologies.
We develop the theory of low-lying eigenstates in nanoscale quantum dots, taking into account the charge density fluctuations and the dot anisotropy characteristic to the nanodevices based on silicon technology. We demonstrate that the interaction effects lead to anomalous peak doublets in the Coulom blocade transport in these systems, in agreement with recent experiments.
Electrical Engineering Department, Princeton University
E-QUAD, Princeton, NJ 08540 USA