A square-root speedup for finding the smallest eigenvalue

التفاصيل البيبلوغرافية
العنوان: A square-root speedup for finding the smallest eigenvalue
المؤلفون: Kerzner, Alex, Gheorghiu, Vlad, Mosca, Michele, Guilbaud, Thomas, Carminati, Federico, Fracas, Fabio, Dellantonio, Luca
سنة النشر: 2023
المجموعة: Quantum Physics
مصطلحات موضوعية: Quantum Physics
الوصف: We describe a quantum algorithm for finding the smallest eigenvalue of a Hermitian matrix. This algorithm combines Quantum Phase Estimation and Quantum Amplitude Estimation to achieve a quadratic speedup with respect to the best classical algorithm in terms of matrix dimensionality, i.e., $\widetilde{\mathcal{O}}(\sqrt{N}/\epsilon)$ black-box queries to an oracle encoding the matrix, where $N$ is the matrix dimension and $\epsilon$ is the desired precision. In contrast, the best classical algorithm for the same task requires $\Omega(N)\text{polylog}(1/\epsilon)$ queries. In addition, this algorithm allows the user to select any constant success probability. We also provide a similar algorithm with the same runtime that allows us to prepare a quantum state lying mostly in the matrix's low-energy subspace. We implement simulations of both algorithms and demonstrate their application to problems in quantum chemistry and materials science.
Comment: 17 pages, 6 figures, all comments are welcome, additional references added
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2311.04379
رقم الانضمام: edsarx.2311.04379
قاعدة البيانات: arXiv