Date/Time
Date(s) - 11/09/2006
3:30 pm - 4:30 pm

Title: Design and control of quantum states in two-dimensional quantum dots

Speaker: Dr. Jordan Kyriakidis

Institute: Dalhousie University, Halifax, Canada

Location: ABB 164

Description:

Quantum dots can be defined electrostatically within a two-dimensional electron gas by applying voltages to nearby metallic gates. These dots behave in some respects like artificial atoms, but exist in an entirely different parameter regime. Perhaps most importantly, interaction effects can be four orders of magnitude larger than in natural atoms. The seminar will discuss several aspects of (mostly) theory and experiment in these systems, all of which depend on the interplay of spin symmetry and strong Coulomb repulsion. One application is quantum computing; a hybrid spin/charge qubit can be defined whose two orthogonal states exhibit identical (single-particle) spin and charge density, and which can be coherently rotated by voltage pulses alone. By coupling two such qubits, a universal set of quantum gates can be constructed. Finally, several outstanding issues regarding steady-state and dynamic (transient) current will be addressed. The challenge for theorists is to construct a satisfactory theory for a many-Fermion system with strong, long-range repulsion, neither isolated nor periodic, driven far from equilibrium.