Quantum cellular automata computing with endohedral fullerenes

Universal quantum computation is performed using global addressing techniques as applied to a physical system of spin entities of two distinct types arranged in an ABABAB sequence. Algorithms are provided for performing global unitary operations on such arrays and thereby providing a framework for performing any logical computations. Simple spin ½ units such as free electrons are provided for, as well as molecular entities. The preferred system consists of an ABAB linear array of Group V endohedrally doped fullerenes which can be reliably manipulated and arrayed on silicon. Each molecule spin site consists of a nuclear spin coupled via a hyperfine interaction to an electron spin. The electron spin of each molecule is in a quartet ground state S = 3/2. Neighboring molecular electron spins are coupled via a magnetic dipole interaction. A quantum cellular automata quantum computing architecture is provided using these molecules by encoding the quantum information on the nuclear spins while using the electron spins as a local bus. The NMR and ESR pulses required to execute the basic cellular automata operations are described.