Grover's Quantum Search Algorithm
Grover's Quantum Search Algorithm
Quantum computers may solve some problems dramatically faster than conventional machines. One example is searching an unordered set for an item with specific properties. A quantum algorithm can find such an item (a "solution") in a time proportional to the square root of the size of the set, which is considerably faster than conventional ("classical") methods on large sets.
This Demonstration compares classical and quantum algorithms for this search problem. The plot shows the probability of finding a solution for each algorithm when run for a specified number of steps. For example, in a 10-item set with one solution, the quantum algorithm performs well with only two steps.