@inproceedings{klappenecker2002engineering, author = {Klappenecker, Andreas and Roetteler, Martin}, title = {Engineering Functional Quantum Algorithms}, year = {2002}, month = {August}, abstract = {Suppose that a quantum circuit with K elementary gates is known for a unitary matrix U, and assume that U^m is a scalar matrix for some positive integer m. We show that a function of U can be realized on a quantum computer with at most O(mK+m^2log m) elementary gates. The functions of U are realized by a generic quantum circuit, which has a particularly simple structure. Among other results, we obtain efficient circuits for the fractional Fourier transform.}, url = {http://approjects.co.za/?big=en-us/research/publication/engineering-functional-quantum-algorithms/}, }