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Vol 46, No 6 (2017)
- Year: 2017
- Articles: 9
- URL: https://journals.rcsi.science/1063-7397/issue/view/11682
Article
Statistical Models and Adequacy Validation for Optical Quantum State Tomography with Quadrature Measurements
Abstract
Mutually complementary quadrature quantum measurements are analyzed and a new method to formulate statistical models of quantum states is proposed. The method is based on the root approach to quantum measurements and includes a procedure for approximating quantum states with reduced finite dimensional models. The efficiency of the proposed approach is demonstrated using numerical experiments. This approach is aimed at achieving the highest possible precision in multiphoton quantum state tomography.
371-378
Single-Photon Response and Spectroscopy of a Photonic Molecule Based on Diamond Microrings
Abstract
The optical properties of a photonic molecule consisting of three diamond microring cavities are theoretically investigated. The probability of single-photon excitation (optical response) of a photonic molecule by a weak laser field in the steady-state mode with regard to the dissipative effects is calculated using the model analogous to the tight binding approximation. It is shown that the spectrum can be fine tuned by depositing additional layers onto the photonic-molecule surface. The dependences of the wavelength of the mode corresponding to the zero-phonon optical transition in the NV center on the thickness of these layers and refractive index of their material are established. The NV center localized in the electromagnetic field antinode effectively interacts with the photonic molecule eigenmode, which can be observed as anticrossing points in the dependences of the optical response of the system on exciting laser and transition frequencies.
379-389
Electromagnetic Modeling, Technology, and Production of Microwave C3MOSHFET Switches on AlGaN/GaN Heterostructures
Abstract
The features of the electromagnetic modeling of a microwave switch for the frequency range of 1–20 GHz, which is then produced by C3MOSHFET technology on AlGaN/GaN heterostructures using high-K dielectrics and contacts with capacitive coupling, are considered.
390-395
The Use of Finite Element Modeling for Calculating the C-V Curve of Capacitor Mems Microphone
Abstract
The C-V curve is an important characteristic of a MEMS microphone as it determines its operating voltage and sensitivity. Due to the complicated geometry of its fixed perforated backplate and thin movable diaphragm, it requires finite element modeling to calculate the C-V curve. Various methods to solve this problem are considered in this work, and implementation of the iterative calculation method using the ANSYS software package is proposed. The results obtained using the iterative method and the two calculating methods of electrostatic interaction built into the ANSYS software are compared and analyzed.
396-403
Monolithic Integrated Circuits for Low-Noise Centimeter-Wave Amplifiers on an AlGaN/AlN/GaN/SiC Heterostructure
Abstract
The results of designing low-noise broadband amplifiers on an AlGaN/AlN/GaN HEMT heterostructure are presented. In the investigations, two variants of low-noise amplifiers executed in a two-cascade circuit are considered and fabricated. The parameters of the fabricated monolithic integrated circuits of lownoise amplifiers are given.
404-407
Total Efficiency of the Optical-to-Terahertz Conversion in Photoconductive Antennas Based on LT-GaAs and In0.38Ga0.62As
Abstract
The total efficiency of the optical-terahertz conversion ηtotal in photoconductive antennas (PCAs) on the basis of different materials (LT-GaAs and In0.38Ga0.62As) under optical laser excitation at wavelengths of 800 and 1030 nm is studied. It is shown that the photoconductive material factor μτ2 has a significant impact on the magnitude of the THz photocurrent and the value of ηtotal. With the use of electromagnetic modeling, the processes of heat transfer are studied and the power of Joule heating in these PCAs is evaluated.
408-413
Electronic Structure of Molecular Switches on Splitters Based on trans-Polyacetylene
Abstract
The electronic characteristics are studied for a Y-splitter based on trans-polyacetylene molecules using analytical calculations in the scope of a tight-binding approximation, as well as an ab initio simulation using the density functional theory (DFT). It is shown that based on such a splitter both a quantum interference transistor and a molecular diode could be developed. A semiphenomenological model of an interference transistor based on the Fano resonance is proposed. The effect of conformational transitions connected with the rotation of branches exerted on the distribution of the density of π-electron is studied.
414-423
Development of the Technology of Magnetron Sputtering Deposition of LiPON Films and Investigation of Their Characteristics
Abstract
The results of developing the technology of magnetron sputtering deposition of a LiPON solid electrolyte and an experimental investigation of its characteristics are presented. The basic processing operations and parameters providing the formation of films of the proper morphology, structure, and elemental and phase composition are described. The data of the measurement of the physical parameters of the films by cyclic voltammetry and potentiometry are represented.
424-432
Effect of the Measuring Signal Parameters on the Error in Capacitance Measurements of a p-n Transition and Determining Its Resistance to Radiation
Abstract
The effect of the measuring signal parameters on the capacitance measurement error of semiconductor diodes is estimated: the form of the distribution function of the results of the measurements and its repeatability and statistical parameters (mean and standard deviation). Methods to reduce the measurement errors are proposed. The parameters of the measuring signal for which the root-mean-square deviation within the sample of the obtained results is minimal are determined. It is shown that the measurement results can have a statistical distribution law different from the Gaussian law. The influence of the measurement error on the recovery of a charge carrier’s distribution is demonstrated. A criterion for determining the level of radiation resistance based on a change in the concentration of charge carriers under the action of a fast neutron flux is proposed.
433-441