Search

A new superconducting element, a cryogenic phase detector (CPD) based on a superconductor-insulator-superconductor junction which could operate with effective bandwidth more than 100 MHz is presented.

The design, fabrication, and testing of the superconducting integrated receiver (SIR) which was developed based on Nb-AlN-NbN-Nb circuits with a gap voltage Vg up to 3.7 mV is presented.

An attempt is made to find out the essential dependence of the phase-locked flux-flow oscillator (FFO) linewidth on its width and idle region dimension and the optimization of the FFO layout. The integrated circuits were used comprising FFO and harmonic mixer (HM) with matching circuits for linewidth measurements and FFO phase locking.

Research involving Josephson Flux Flow Oscillators (FFO) is described and discussed.

A submillimeter heterodyne spectrometer with a superconducting local oscillator is described and discussed.

Enterprise email classification in the sales engagement platform is a challenge due to its evolving asynchronous conversational context during the sales process and differences across industries and organizations. This is further exacerbated by the limited amount of labeled emails due to security and privacy constraints. The leaderboard success of using pretrained language models (LMs) such as BERT and various transfer learning techniques promises a paradigm shift to natural language processing, yet the recipe for applying high performance transfer learning (HPTL) in practical applications remains unclear. This article investigates applying HPTL to sales engagement email classification through a series of experiments and analysis. The experiment datasets include two different organizations' emails. The contribution of this paper is 4‐fold: (a) analysis and characterization of the email corpora from different organizations; (b) identification of the best combinations of pre‐trained LMs under different modeling architectures; (c) study of the impact and trade‐off of limited labeled data on the model accuracy and training time; and (d) characterization and study of the impact of different orgs' datasets on the model accuracy. Our results showed that a practical winning recipe that uses BERT‐finetuning with as few as 500 labeled training examples can consistently outperform significantly with reasonable training time among all models evaluated. [ABSTRACT FROM AUTHOR]

Research describing a low noise, radio frequency amplifier based on a dc superconducting quantum interference device is presented. In particular a novel signal launching system for the device coupling is developed.

Research describing phase locking and linewidth measurements for a Josephson flux flow oscillator is presented. In particular the use of an off-chip harmonic multiplier is investigated.

Superconducting integrating receivers were fabricated and a yield analysis undertaken.

A study investigated the so-called knee structure dependence on the thickness of the base Nb electrode and additional Al layer in Nb-AlOx-Nb tunnel junctions. Conditions for the fabrication of the ideal SIS tunnel junctions with knee-free IVC have been determined and are realized at ultra-thin Al and bottom Nb layers or at introduction of an additional Al interlayer in the base Nb electrode. Experimental methods and results are presented.

Research was conducted to examine the Josephson Flux-Flow Oscillator (FFO) linewidth which was measured in the resonant regime at V < 915 microV for niobium-aluminum oxide-niobium tunnel junctions. A novel on chip Cherenkov radiation flux-flow oscillator (CRFFO) is proposed to overcome the fundamental linewidth broadening. Results show induced resonances on the CRFFOs current-voltage curves with tunable frequency.

The development of a novel type of ultra broad band superconductor-insulator-superconductor (SIS) low noise radiometer is described. The possibility of making a low noise SIS radiometer with a detection bandwidth many tens of times larger than in the standard design is demonstrated. The new type of a new band operation of a mixer with a SIS quasi particle tunnel junction employs the simultaneous mixing at the different frequencies of the local oscillator with a comb type spectrum.

A detailed investigation of the microwave linewidth of Nb-AlO(sub x)-Nb flux flow oscillators was conducted. An improved method based on harmonic mixing in the frequency range 250-600 GHz was used to calculate the dependence of the flux flow oscillators linewidth on the junctions parameters. Results illustrate the ability to decrease the intrinsic linewidth of a Josephson oscillator by an external electronic phase locked loop (PLL) system if the PLL bandwidth is larger than the initial oscillator linewidth.

Copyright of Contributii Botanice is the property of Contributii Botanice and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)