We consider a mechanism to generate controllable qudit-qudit interactions in a charge-position paradigm for a quantum computer, through the use of auxiliary states. By controlling the tunneling rates onto these auxiliaries from the qudits proper, we can controllably switch the entangling operations. We consider a practical architecture in which to realize such a computer and examine the associated Hilbert space dimension.
@article{arxiv.quant-ph/0305052,
title = {Implementation of controlled multi-qudit operations for a solid-state quantum computer based on charge qudits},
author = {S. G. Schirmer and A. D. Greentree and D. K. L. Oi},
journal= {arXiv preprint arXiv:quant-ph/0305052},
year = {2007}
}