Search academic texts

Information × Registration Number 0224U001134, 0120U104878 , R & D reports Title Nonclassical and hybrid correlations of quantum systems under realistic conditions popup.stage_title Head Semenov Andrii Oleksandrovych, Доктор фізико-математичних наук Registration Date 17-01-2024 Organization М.М.Bogolyubov Institute of Theoretical Physics of the National Academy of Sciences of Ukraine popup.description2  Object of research: quantum light, free-space quantum channels, superconducting nanowire single-photon detectors, Josephson photomultipliers. Objectives: a theoretical description for nonclassical properties of electromagnetic radiation propagating through the atmosphere or locally processed and detected by realistic photocounters. Methods: quantum phase space, theory of quantum measurements, differential geometry, convex geometry, phase screen method. Results: A theory for two types of photodetection techniques is developed accounting for the realistic ability to discriminate between numbers of photons. The first type relates to superconducting nanowire single-photon detectors, which are affected by dead and relaxation times, as well as by memory effects from previous measurement time windows. The second type refers to Josephson photomultipliers, which sequentially count the number of microwave photons in a resonator. For atmospheric quantum channels, numerical modeling is performed, including consideration of time correlations of transmittance efficiencies. An empirical model of the Beta distribution for the probabilities of transmittance in atmospheric channels is proposed. The ability of atmospheric channels to preserve quantum entanglement between successive light pulses up to times of the order of milliseconds is demonstrated. It is also shown that preselection by transmittance is a powerful resource for preserving nonclassical properties of light propagated through such channels. Tight inequalities that enable to identify optical nonclassicality and nonclassical correlations that are weaker than Bell nonlocality are derived. Validation methods for Gaussian Boson Sampling schemes with realistic photon-number resolution are developed. Product Description popup.authors Yeremenko Ivan S. Baskov Roman A. Klen Mykyta D. Kliushnichenko Olexsandr V. Kovtonyuk Vadym S. Semenov Andrij О. Sokolov Andrii M. Stoliarov Yevgen V. Uzunova Vira O. popup.nrat_date 2024-01-17 Close