  Advances in recent years have made it possible to explore quantum dots as a
viable technology for scalable quantum information processing. Charge qubits
for example can be realized in the lowest bound states of coupled quantum dots
and the precision control of the confinement potential allows for the
realization of a full set of universal qubit gates, including arbitrary
single-qubit rotations and two-qubit C-NOT gates. In this work we describe a
novel scheme for implementing quantum random walks on arbitrarily complex
graphs by extending these elementary operations to the control of a
two-dimensional quantum dot grid. As single-qubit rotations constitute the
essential building blocks of our implementation scheme, we also present
numerical simulations of one such mechanism by directly solving the
corresponding time-dependent Schrodinger equation.
