A quantum algorithm that deletes marked states from an arbitrary database

Abstract

We present a general quantum deletion algorithm that deletes M marked states from an N-item quantum database with arbitrary initial distribution. The general behavior of this algorithm is analyzed, and analytic result is given. When the number of marked states is no more than 3N/4, this algorithm requires just a single query, and this achieves exponential speedup over classical algorithm. © 2013 The Author(s).