2019/12/31 by Dmitry Grinko, Julien Gacon, Christa Zoufal +1 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1038/s41534-021-00379-1
published as npj Quantum Inf 7, 52 (2021) · fixed typos, figures, references
arxiv created 2021/04/19 · arxiv updated 2021/04/20
We introduce a new variant of Quantum Amplitude Estimation (QAE), called Iterative QAE (IQAE), which does not rely on Quantum Phase Estimation (QPE) but is only based on Grover's Algorithm, which reduces the required number of qubits and gates. We provide a rigorous analysis of IQAE and prove that it achieves a quadratic speedup up to a double-logarithmic factor compared to classical Monte Carlo simulation. Furthermore, we show with an empirical study that our algorithm outperforms other known QAE variants without QPE, some even by orders of magnitude, i.e., our algorithm requires significantly fewer samples to achieve the same estimation accuracy and confidence level.