Condensed Matter Physics Seminar

2 p.m., Thursday, October 4, 2001
Room 1201, Physics Building

 How to Make a Quantum Computer in 5 Easy* Steps

Jeremy Levy

(Department of Physics and Astronomy, University of Pittsburgh)

Abstract:  Quantum computers promise to exploit the fundamental laws of quantum mechanics to produce staggering speedups of certain kinds of calculations. However, the physical realization of quantum computers is still in its infancy. In this talk, I will describe a proposal to construct a quantum information processor using ferroelectrically coupled Ge/Si quantum dots. The spin of single electrons form the fundamental qubits. Small (<10 nm diameter) Ge quantum dots are optically excited to create spin polarized electrons in Si. The static polarization of an epitaxial ferroelectric thin film confines electrons laterally in the semiconductor; spin interactions between nearest neighbor electrons are mediated by the nonlinear process of optical rectification. Single qubit operations are achieved through "g-factor engineering" in the Ge/Si structures; spin-spin interactions occur through Heisenberg exchange, controlled by ferroelectric gates. A method for reading out the final state may be achieved using single electron transistors, as described by Kane et al. Initial steps toward the realization of such a system will also be described.
Host:  Dennis Drew
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