Mapping quantum algorithms to multi-core quantum computing architectures

Current monolithic quantum computer architectures have limited scalability. One promising approach for scaling them up is to use a modular or multi-core architecture, in which different quantum processors (cores) are connected via quantum and classical links. This new architectural design poses new challenges such as the expensive inter-core communication. To reduce these movements when executing a quantum algorithm, an efficient mapping technique is required. In this paper, a detailed critical discussion of the quantum circuit mapping problem for multi-core quantum computing architectures is provided. In addition, we further explore the performance of a mapping method, which is formulated as a partitioning over time graph problem, by performing an architectural scalability analysis

Apophis planetary defense campaign

We describe results of a planetary defense exercise conducted during the close approach to Earth by the near-Earth asteroid (99942) Apophis during 2020 December–2021 March. The planetary defense community has been conducting observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. These community-led global exercises were carried out with the support of NASA's Planetary Defense Coordination Office and the International Asteroid Warning Network. The Apophis campaign is the third in our series of planetary defense exercises. The goal of this campaign was to recover, track, and characterize Apophis as a potential impactor to exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication. Based on the campaign results, we present lessons learned about our ability to observe and model a potential impactor. Data products derived from astrometric observations were available for inclusion in our risk assessment model almost immediately, allowing real-time updates to the impact probability calculation and possible impact locations. An early NEOWISE diameter measurement provided a significant improvement in the uncertainty on the range of hypothetical impact outcomes. The availability of different characterization methods such as photometry, spectroscopy, and radar provided robustness to our ability to assess the potential impact risk

Three-level buck converter for envelope tracking

Abstract- This paper proposes a three-level buck converter for efficient wide-bandwidth envelope tracking in RF power amplifiers (RFPA). The focus is on low-power battery-operated systems, and the goal is to enable practical implementation of the Envelope Elimination and Restoration (EER) technique, which theoretically allows realization of a highly linear, highly efficient RFPA for non-constant envelope modulations. In terms of ripple, switching frequency and bandwidth tritdeoffs, it is shown that the three-level buck converter is similar to the two-phase configuration, while employing a single inductor in the power stage. Additionally, a digital control technique for regulation of the flying capacitor voltage is proposed to ensure signal tracking fidelity. Experimental re!iults show the improved performance of a three-level buck converter prototype as regards efficiency and ripple rejection for the illustrative case of tracking the envelope of a two-tone test signal. I

A 2 GHz - 8.7 GHz Wideband Balun-LNA with Noise Cancellation and Gain Boosting

A wideband Balun-LNA covering the operation frequency range of magnetic tunnel junction Spin Torque Oscillator is presented. The LNA is a combination of common-source and cross-coupled common-gate stages, which provides wideband matching and noise cancellation, as well as gain boosting. The internal feedback introduced by the cross-coupling allows an additional degree of freedom to select transistor sizes and bias by decoupling the impedance matching, noise, and gain imbalance trade-offs which are present in similar topologies. Two LNAs using the proposed technique are designed in 65nm CMOS. The LNAs have a simulated bandwidth of  2 GHz - 8.7 GHz, gain of 16 dB, IIP3 of -3.5 dBm,  and NF &lt; 3.8 dB while consuming 3.72 mW from a 1.2 V power supply.QC 20130114</p

Экологический туризм: развитие и перспективы в лесном хозяйстве Беларуси

A wideband Balun-LNA covering the operation frequency range of magnetic tunnel junction Spin Torque Oscillator is presented. The LNA is a combination of common-source and cross-coupled common-gate stages, which provides wideband matching and noise cancellation, as well as gain boosting. The internal feedback introduced by the cross-coupling allows an additional degree of freedom to select transistor sizes and bias by decoupling the impedance matching, noise, and gain imbalance trade-offs which are present in similar topologies. Two LNAs using the proposed technique are designed in 65nm CMOS. The LNAs have a simulated bandwidth of  2 GHz - 8.7 GHz, gain of 16 dB, IIP3 of -3.5 dBm,  and NF &lt; 3.8 dB while consuming 3.72 mW from a 1.2 V power supply.QC 20130114</p