QUANTUM ORACLES IN TERMS OF UNIVERSAL GATE SET
Yuji L. Tanaka, Tsubasa Ichikawa, Masahito Tada-Umezaki, Yukihiro Ota, Mikio Nakahara · International Journal of Quantum Information · 2011
We present a systematic construction of quantum circuits implementing Grover's database search algorithm for arbitrary number of targets. We introduce a new operator which flips the sign of the targets and evaluate its circuit complexity. We find the condition under which the circuit complexity of the database search algorithm based on this operator is less than that of the conventional one.