  We propose a universal quantum computer based on a chain of carbon nanotube
rotators where one metallic plate is attached to each rotator. The dynamical
variable is the rotational angle $\phi$. The attached plate connected to ground
electrostatically interacts with two fixed plates. Two angle positions $\phi
=0,\pi$ are made stable by applying a voltage difference between the attached
plate and the two fixed plates. We assign $\phi =0$ and $\pi $ to the qubit
states $|0\rangle$ and $|1\rangle $. Then, considering a chain of rotators, we
construct the arbitrary phase-shift gate, the NOT gate and the Ising gate,
which constitute a set of universal quantum gates. They are executed by
controlling the voltage between various plates.
