Observation of non-Markovian micro-mechanical Brownian motion

All physical systems are to some extent open and interacting with their environment. This insight, basic as it may seem, gives rise to the necessity of protecting quantum systems from decoherence in quantum technologies and is at the heart of the emergence of classical properties in quantum physics. The precise decoherence mechanisms, however, are often unknown for a given system. In this work, we make use of an opto-mechanical resonator to obtain key information about spectral densities of its condensed-matter heat bath. In sharp contrast to what is commonly assumed in high-temperature quantum Brownian motion describing the dynamics of the mechanical degree of freedom, based on a statistical analysis of the emitted light, it is shown that this spectral density is highly non-Ohmic, reflected by non-Markovian dynamics, which we quantify. We conclude by elaborating on further applications of opto-mechanical systems in open system identification.Comment: 5+6 pages, 3 figures. Replaced by final versio

Parametric Oscillation of a Moving Mirror Driven by Radiation Pressure in a Superconducting Fabry-Perot Resonating System

A moving pellicle superconducting mirror, which is driven by radiation pressure on its one side, and by the Coulomb force on its other side, can become a parametric oscillator that can generate microwaves when placed within a high-Q superconducting Fabry-Perot resonator system. A paraxial-wave analysis shows that the fundamental resonator eigenmode needed for parametric oscillation is the TM011 mode. A double Fabry-Perot structure is introduced to resonate the pump and the idler modes, but to reject the parasitic anti-Stokes mode. The threshold for oscillation is estimated based on the radiation-pressure coupling of the pump to the signal and idler modes, and indicates that the experiment is feasible to perform.Comment: 30 pages, 6 figures, part of proceedings of FQMT 2011 conference in Prague, Czech Republi

Моделювання поля антенної решітки на циліндричних діелектричних резонаторах

The general principles of analytical computing of cylindrical dielectric resonators system field is stated. The 5 dielectric resonators' plane lattice is considered, the theoretical and experimental results of its characteristics' modeling are given.Изложена общая методика аналитического расчета полей систем диэлектрических резонаторов. Рассмотрена плоская решетка из 5-ти диэлектрических резонаторов, приведены теоретические и экспериментальные результаты моделирования ее характеристик.Викладено загальну методику аналітичного розрахунку полів систем діелектричних резонаторів. Розглянуто пласку решітку з 5-ти діелектричних резонаторів, наведено теоретичні і експериментальні результати моделювання її характеристик.  

Stripe delay filters

Полный текст доступен на сайте издания по подписке: http://radio.kpi.ua/article/view/S002134701604004XThere are considered constructions of microsized stripe delay filters, which are realized on a basis of ceramic materials with high dielectric permittivity. Delay time of non-minimal phase filters is 7–12 ns at frequencies of 1900 MHz with relative bandwidth of 3.6–3.85%. Filters dimensions are comparable with ones used in portable communication devices. Dimensions of researched three-resonator filter at frequency of 1900 MHz are 8.4×5×2 mm with material dielectric permittivity εᵣ = 92, and 5-resonator filter ones are 9.2×8.6×2 mm. Filters are different from traditional delay filters. Two filters of considered ones contain odd resonator number and the third one contains four resonators and it has two cross couplings. The basis of the filters is amount of step-impedance stripe resonators pairs located close to each others whose electromagnetic coupling behavior is capacitive. There are represented the results of frequency characteristics simulation for different delay filters.Рассмотрены новые конструкции миниатюрных полосковых фильтров задержки, которые реализованы на керамических материалах с высокой диэлектрической проницаемостью. Время задержки в новых неминимально-фазовых фильтрах составляет 7–12 нс на частотах около 1900 МГц с относительной шириной полосы частот 3,6–3,85%. Размеры фильтров соизмеримы с размерами микроволновых керамических фильтров, используемых в портативных устройствах связи. Размеры исследованного в работе трехрезонаторного фильтра задержки на частоте 1900 МГц составили 8,4×5×2 мм при диэлектрической проницаемости материала εᵣ = 92, а 5-резонаторного фильтра — 9,2×8,6×2 мм. Фильтры отличаются от традиционных фильтров задержки. Два из рассмотренных фильтров содержат нечетное число резонаторов, а третий имеет четыре резонатора и обладает двумя перекрестными связями. Основу фильтров составляют пары близко расположенных друг к другу ступенчато-импедансных полосковых резонаторов, электромагнитная связь между которыми носит емкостной характер. Приведены результаты моделирования частотных характеристик различных фильтров задержки

Observation of non-Markovian micromechanical Brownian motion

All physical systems are to some extent open and interacting with their environment. This insight, basic as it may seem, gives rise to the necessity of protecting quantum systems from decoherence in quantum technologies and is at the heart of the emergence of classical properties in quantum physics. The precise decoherence mechanisms, however, are often unknown for a given system. In this work, we make use of an opto-mechanical resonator to obtain key information about spectral densities of its condensed-matter heat bath. In sharp contrast to what is commonly assumed in high-temperature quantum Brownian motion describing the dynamics of the mechanical degree of freedom, based on a statistical analysis of the emitted light, it is shown that this spectral density is highly non-Ohmic, reflected by non-Markovian dynamics, which we quantify. We conclude by elaborating on further applications of opto-mechanical systems in open system identification