The given thesis subject is quantum tomography protocols for states and processes. The goal is to experimentally validate and develop adaptive tomography protocols to improve the reconstruction accuracy of unknown quantum states or processes compared to existing approaches. Spontaneous parametric down conversion in nonlinear crystals was used to prepare quantum states. The thesis results can be applied in the practical implementation of quantum computing devices and their debugging. This thesis demonstrated experimentally that the adaptive Bayesian tomography method has a higher accuracy in reconstructing unknown quantum states and processes compared to a random measurement strategy. Also, this adaptive method is less susceptible to hardware errors. A high-dimensional two-component system tomography algorithm was developed and experimentally validated, and a shadow tomography method was also investigated.
Download (in Russian)This thesis is devoted to studying the spatial correlation properties of spontaneous parametric down-conversion. The thesis also proposes an original method for spatial-mode-detector tomography and examines quantum interference in a Young scheme.
Download (in Russian)This thesis is devoted to the new methods development for controlling the frequency-angular spectrum of a biphoton field, an experimental and theoretical study of these methods capabilities, and a comparison with the existing methods.
Download (in Russian)This thesis is devoted to the experimental study of multilevel quantum systems implemented using various biphoton-field degrees of freedom. Issues related to quantum state preparation and measurement are considered in their possible use context in various quantum information protocols.
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