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Information × Registration Number 0224U033348, (0123U103073) , R & D reports Title Mesoscopic systems for quantum interferometry and single-photon detection popup.stage_title Розвиток напівкласичної та побудова квантової моделі детектора мікрохвильових фотонів, заснованого на потоковому кудіті. Теоретичне дослідження гігантського атома. Head Ilinskaia Olha O., к.ф.-м.н. Registration Date 25-12-2024 Organization B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine popup.description1 The goal of the study is theoretical investigation of mesoscopic quantum systems such as double quantum dot and flux qubit. In particular, it is planned to describe realistic systems and to correlate theoretical results with experimental ones. Semiclassical and quantum theories for such systems will be built and quantum devices based on these systems – interferometers and detectors of microwave photons – will be investigated. popup.description2 ● At the 2024 stage of the Project, the theoretical study of the microwave photon detector based on the flux qudit was continued, and the calculation of the dynamics describing the readout and reset stages of the detection was updated, taking into account that the relaxation rates are functions of the qudit’s eigenenergies and eigenfunctions. The time dependence of the relaxation rates at the reset stage and its influence on the dynamics of the occupations of the qudit levels at this stage were found; it was found out that dissipation occurs only in the vicinity of the quasicrossing points of levels and is noticeable only for the last two Landau-Zener-Stückelberg-Majorana transitions. A theoretical analysis of a giant atom, a system formed by connecting a multilevel system to a transmission line at several points, was carried out. For a special case of a two-level giant atom, the Lindblad equation was solved and interference patterns were constructed for the system under study. In the further theoretical study of the silicon-based double quantum dot, the dynamics describing the different modes of operation of the system was obtained by solving the Lindblad equation. The study of a transmon qubit connected to a semi-infinite transmission line was continued. Some interference patterns were obtained, namely, the dependence of the upper level occupation on the probe signal frequency and pump amplitude at small pump signal frequencies. Also, the dynamics of this system was investigated and the dependence of the transmon upper level occupation on time and probe signal frequency, for different values of the probe signal amplitude and relaxation rate at a fixed pump signal frequency was plotted. The results obtained can find practical application in designing and conducting experiments.   Product Description popup.authors popup.nrat_date 2024-12-25 Close