Information scrambling and the growth of errors in noisy tomography -- a quantum signature of chaos

التفاصيل البيبلوغرافية
العنوان: Information scrambling and the growth of errors in noisy tomography -- a quantum signature of chaos
المؤلفون: Sahu, Abinash, Varikuti, Naga Dileep, Madhok, Vaibhav
سنة النشر: 2022
المجموعة: Nonlinear Sciences
Quantum Physics
مصطلحات موضوعية: Quantum Physics, Nonlinear Sciences - Chaotic Dynamics
الوصف: How does quantum chaos lead to rapid scrambling of information as well as errors across a system when one introduces perturbations in the dynamics? What are its consequences for the reliability of quantum simulations and quantum information processing? We employ continuous measurement quantum tomography as a paradigm to study these questions. The measurement record is generated as a sequence of expectation values of a Hermitian observable evolving under repeated application of the Floquet map of the quantum kicked top. Interestingly, we find that the reconstruction fidelity initially increases regardless of the degree of chaos or the strength of perturbations in the dynamics. For random states, when the measurement record is obtained from a random initial observable, the subsequent drop in the fidelity obtained is inversely correlated to the degree of chaos in the dynamics. More importantly, this also gives us an operational interpretation of Loschmidt echo for operators by connecting it to the performance of quantum tomography. We define a quantity to capture the scrambling of errors, an out-of-time-ordered correlator (OTOC) between two operators under perturbed and unperturbed system dynamics that serves as a signature of chaos and quantifies the spread of errors. Our results demonstrate not only a fundamental link between Loschmidt echo and scrambling of errors, as captured by OTOCs, but that such a link can have operational consequences in quantum information processing.
Comment: 10 pages, 4 figures, new title, minor changes in the abstract and the main text with better presentation
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2211.11221
رقم الأكسشن: edsarx.2211.11221
قاعدة البيانات: arXiv