München 2004 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 25: Quanteneffekte II
Q 25.4: Vortrag
Dienstag, 23. März 2004, 17:30–17:45, HS 218
Coherent propagation of electron wavepackets in arrays of coupled quantum dots — •Georgios Nikolopoulos1,2, David Petrosyan2, and Peter Lambropoulos2 — 1Institut für Angewandte Physik, Technische Universität Darmstadt, D-64289 Darmstadt — 2Institute of Electronic Structure and Laser, FORTH, P.O.Box 1527, Heraklion, GR-71110 Crete
Quantum computing schemes where the qubits are represented by spin-states of single electrons confined in individual quantum dots(QDs), are of particular interest to current research, since they are considered to be the most promising candidates for making large quantum computers. Motivated by the necessity of understanding the dynamics of electron wavepackets in the presence of disorder and dissipation and to investigate the conditions under which coherent transport can be achieved, we study the dynamics of few-electron transport in a linear array of tunnel-coupled quantum dots. The electrons are considered initially well localized at the ends of the chain and their spin-sates are well defined. We find that this system exhibits a rich variety of coherent phenomena, ranging from electron wavepacket propagation and interference to many-particle bonding and collision. Furthermore, we show that choosing the couplings between adjacent QDs (optimal coupling) judiciously, one may achieve non-dispersive propagation of the electron wavepacket. A possible scenario capable of producing controllable mesoscopically separated EPR correlated pairs of electrons is presented.