Nanotech 2002 Vol. 1
Nanotech 2002 Vol. 1
Technical Proceedings of the 2002 International Conference on Modeling and Simulation of Microsystems

Quantum Effects, Quantum Devices and Spintronics Chapter 10

Gain in a Semiconductor Waveguide Qubit

Authors: J. Harris, R. Akis and D.K. Ferry

Affilation: Arizona State University, United States

Pages: 528 - 531

Keywords: qubit, coupled quantum wires, mode-matching, quantum waveguide

Recently, it has been suggested that it may be possible to use combinations of coupled quantum wire waveguides to form quantum computational qubits [1],[2]. However, there are several related problems intrinsic to this approach. First, in order to completely switch the electron probability wave from one waveguide to another, the length of the region in which the two waveguides are coupled must be tuned quite precisely. In addition, even with a well-tuned coupling length, it appears that complete transmission of the probability wave cannot be achieved [2]. Both of these problems may be mitigated by the addition of a bias along the length of the quantum wires – this would effectively alter the coupling length and may also increase the transmission gain. We show that adding this bias does not provide gain to overcome the lack of 100% coupling between the two guides, but can be used to compensate for imprecision in the length of the device’s coupling region.

ISBN: 0-9708275-7-1
Pages: 764