Crystal lattice quantum computer

A quantum computer can be constructed from nuclear spins in a crystal latti ce of a rare-earth monophosphide such as cerium-monophosphide (CeP). The 1/ 2 spin of a P-31 nucleus can be used to represent a quantum bit ('qubit') w ith a relatively long relaxation time. In a CeP crystal lattice, P-31 nucle i are periodically situated in three dimensions at distances of about 12 An gstrom. The application of a static magnetic field gradient in one directio n causes differences in the Zeeman frequencies of separate nuclei. This all ows thousands of distinct qubits to be individually addressed. Initializati ons of the qubits can be done efficiently by the Pound-Overhauser double re sonance effect on the nuclear spins and the antiferromagnetically ordered 4 f electron spins of cerium ions. Logic operations can be performed by simpl e pulse sequences, and computational results after logic operations can be measured by the nuclear magnetic resonance of neighboring nuclei, or the el ectron resonance of neighboring 4f electrons of cerium ions.