Robustness of different modifications of Grover’s algorithm based on generalized Householder reflections with different phases

Abstract

In this work we study five Grover’s algorithm modifications, where each iteration is constructed by two generalized Householder reflections, against inaccuracies in the phases. By using semi-empirical methods, we investigate various characteristics of the dependence between the probability to find solution and the phase errors. The first of them is the robustness of the probability to errors in the phase. The second one is how quickly the probability falls beyond the stability interval. And finally, the average success rate of the algorithm when the parameters are in the range of the highly robust interval. Two of the modifications require usage of the same Grover operator each iteration and in the other three it differs. Those semi-empirical methods give us the tool to make prediction of the quantum algorithm modifications’ overall behavior and compare them for even larger register size.

Keywords

• Quantum Information
• Quantum Algorithms
• Grover’s algorithm
• Quantum Search
• Generalized Householder Reflection
• Logistic Regression