Broadband SNAIL parametric amplifier with microstrip impedance transformer

Josephson parametric amplifiers have emerged as a promising platform for quantum information processing and squeezed quantum states generation. Travelling wave and impedance-matched parametric amplifiers provide broad bandwidth for high-fidelity single-shot readout of multiple qubit superconducting circuits. Here, we present a quantum-limited 3-wave-mixing parametric amplifier based on superconducting nonlinear asymmetric inductive elements (SNAILs), whose useful bandwidth is enhanced with an on-chip two-section impedance-matching circuit based on microstrip transmission lines. The amplifier dynamic range is increased using an array of sixty-seven SNAILs with 268 Josephson junctions, forming a nonlinear quarter-wave resonator. Operating in a current-pumped mode, we experimentally demonstrate an average gain of $17 dB$ across $300 MHz$ bandwidth, along with an average saturation power of $- 100 dBm$, which can go as high as $- 97 dBm$ with quantum-limited noise performance. Moreover, the amplifier can be fabricated using a simple technology with just a one e-beam lithography step. Its central frequency is tuned over a several hundred megahertz, which in turn broadens the effective operational bandwidth to around $1.5 GHz$.Comment: 7 pages, 3 figure

High-Q trenched aluminum coplanar resonators with an ultrasonic edge microcutting for superconducting quantum devices

Dielectric losses are one of the key factors limiting the coherence of superconducting qubits. The impact of materials and fabrication steps on dielectric losses can be evaluated using coplanar waveguide (CPW) microwave resonators. Here, we report on superconducting CPW microwave resonators with internal quality factors systematically exceeding 5x106 at high powers and 2x106 (with the best value of 4.4x106) at low power. Such performance is demonstrated for 100-nm-thick aluminum resonators with 7-10.5 um center trace on high-resistivity silicon substrates commonly used in quantum Josephson junction circuits. We investigate internal quality factors of the resonators with both dry and wet aluminum etching, as well as deep and isotropic reactive ion etching of silicon substrate. Josephson junction compatible CPW resonators fabrication process with both airbridges and silicon substrate etching is proposed. Finally, we demonstrate the effect of airbridges positions and extra process steps on the overall dielectric losses. The best quality fa ctors are obtained for the wet etched aluminum resonators and isotropically removed substrate with the proposed ultrasonic metal edge microcutting.Comment: 6 pages, 2 figure

Эффективность применения модификаций препарата Суперстим в малых дозах на этапе адаптации микрорастений жимолости (Lonicera L.) подсекции синей (Caeruleae Rehd.) к нестерильным условиям с учетом последействия на этапе доращивания

Relevance. In recent years, interest in the edible honeysuckle culture has increased in Russia, the wide distribution of which is hampered by the lack of quality planting material. The technology of clonal micropropagation allows for a short time to obtain a large amount of honeysuckle planting material, more than a thousand regenerated plants per year from one meristematic apex introduced into an in vitro culture. It is hundreds of times more than in traditional methods of vegetative propagation. Adaptation to non-sterile conditions is the final and most crucial stage of clonal micropropagation, the loss of which can be from 50 to 90%. It should be noted that there is practically no research on how the further development of adapted honeysuckle plants takes place during subsequent growing.Methods. Researching of growth regulators of the new generation Superstim 1 and Superstim 2 effect in low and ultra-low doses on the survival rates and development of honeysuckle plants at the stages of adaptation subsequent growing.Results. Superstim 1 is more effective at physiological concentrations – 1 x 10-7 and in the field of ultra-low doses – 1 x 10-14, 1 x 10-15%. At the stage of subsequent growing, a positive after-effect of physiological concentrations – 1x10-3 and 1x10-7 was observed, and an ultra-low dose – 1x10-17%. The growth regulator Superstim 2 at the stages of adaptation and subsequent growing is effectively used only in one concentration – 1x10-16%. The additional foliar treatments at the stage of subsequent growing are not necessary. Актуальность. В последние годы в России увеличивается интерес к культуре жимолости съедобной, широкое распространение которой сдерживается из-за дефицита качественного посадочного материала. Технология клонального микроразмножения позволяет за короткий срок получить большое количество посадочного материала жимолости, более тысячи растений-регенерантов в год из одного введенного в культуру in vitro меристематического апекса, что в сотни раз больше, чем при использовании традиционных методов вегетативного размножения. Адаптация к нестерильным условиям является заключительным и наиболее ответственным этапом клонального микроразмножения, потери на котором могут составлять от 50 до 90% мериклонов. Следует отметить, что практически нет исследований о том, каким образом происходит дальнейшее развитие адаптированных растений жимолости при доращивании.Методика. Проведено изучение влияния препаратов нового поколения Суперстим 1 и Суперстим 2 в малых и сверхмалых дозах на показатели приживаемости и развития растений жимолости на этапах адаптации и доращивания.Результаты. Выявлено, что препарат Суперстим 1 более эффективен в физиологической концентрации – 1x10-7% и в области сверхмалых доз – 1x10-14, 1x10-15%. На этапе доращивания выявлено положительное последействие физиологических концентраций – 1x10-3, 1x10-7%, и сверхмалой дозы – 1x10-17%. Препарат Суперстим 2 на этапах адаптации и доращивания эффективно применять только в одной концентрации – 1x10-16%. В дополнительных некорневых обработках на этапе доращивания нет необходимости.

High-Q trenched aluminum coplanar resonators with an ultrasonic edge microcutting for superconducting quantum devices

Abstract Dielectric losses are one of the key factors limiting the coherence of superconducting qubits. The impact of materials and fabrication steps on dielectric losses can be evaluated using coplanar waveguide (CPW) microwave resonators. Here, we report on superconducting CPW microwave resonators with internal quality factors systematically exceeding 5 × 106 at high powers and 2 × 106 (with the best value of 4.4 × 106) at low power. Such performance is demonstrated for 100-nm-thick aluminum resonators with 7–10.5 um center trace on high-resistivity silicon substrates commonly used in Josephson-junction based quantum circuit. We investigate internal quality factors of the resonators with both dry and wet aluminum etching, as well as deep and isotropic reactive ion etching of silicon substrate. Josephson junction compatible CPW resonators fabrication process with both airbridges and silicon substrate etching is proposed. Finally, we demonstrate the effect of airbridges’ positions and extra process steps on the overall dielectric losses. The best quality factors are obtained for the wet etched aluminum resonators and isotropically removed substrate with the proposed ultrasonic metal edge microcutting