Designing exceptional-point-based graphs yielding topologically guaranteed quantum search

التفاصيل البيبلوغرافية
العنوان: Designing exceptional-point-based graphs yielding topologically guaranteed quantum search
المؤلفون: Liu, Quancheng, Kessler, David A., Barkai, Eli
سنة النشر: 2022
المجموعة: Condensed Matter
Quantum Physics
مصطلحات موضوعية: Quantum Physics, Condensed Matter - Statistical Mechanics
الوصف: Quantum walks underlie an important class of quantum computing algorithms, and represent promising approaches in various simulations and practical applications. Here we design stroboscopically monitored quantum walks and their subsequent graphs that can naturally boost target searches. We show how to construct walks with the property that all the eigenvalues of the non-Hermitian survival operator, describing the mixed effects of unitary dynamics and the back-action of measurement, coalesce to zero, corresponding to an exceptional point whose degree is the size of the system. Generally, the resulting search is guaranteed to succeed in a bounded time for any initial condition, which is faster than classical random walks or quantum walks on typical graphs. We then show how this efficient quantum search is related to a quantized topological winding number and further discuss the connection of the problem to an effective massless Dirac particle.
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2202.03640
رقم الأكسشن: edsarx.2202.03640
قاعدة البيانات: arXiv