Programmable Quantum Gate Arrays
Abstract
We show how to construct quantum gate arrays that can be programmed to perform different unitary operations on a data register, depending on the input to some program register. It is shown that a universal quantum gate arraya gate array which can be programmed to perform any unitary operationexists only if one allows the gate array to operate in a probabilistic fashion. Thus it is not possible to build a fixed, general purpose quantum computer which can be programmed to perform an arbitrary quantum computation.
 Publication:

Physical Review Letters
 Pub Date:
 July 1997
 DOI:
 10.1103/PhysRevLett.79.321
 arXiv:
 arXiv:quantph/9703032
 Bibcode:
 1997PhRvL..79..321N
 Keywords:

 Quantum Physics
 EPrint:
 3 pages, REVTEX. Submitted to Phys. Rev. Lett