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LC VCOs with low phase noise (PN) and an octave frequency-tuning range (FTR) are required for multistandard communication devices, software-defined radios, and wireline data links. A viable popular approach is to exploit multicore mode-switching VCOs for two reasons: (1) their PN improves linearly by in-phase coupling of N identical VCOs; (2) the resonant-mode switching enhances the VCO FTR without degrading the tank quality factor (Q) as no RF current ideally flows through lossy mode-selection switches. However, it is still challenging for dual-mode VCOs to achieve a competitive FoM while covering an octave FTR at oscillation frequencies (F_OSC) above 6GHz [1]. To enhance the number of oscillation modes to 3, [2] added a center-loop inductor (L_C) to a transformer, as shown in Fig. 9.2.1. However, a large FTR gap is measured, since the transformer windings should be strongly coupled to accommodate L_C, The authors of [3] and [4] realized a triple- and quad-mode operation, respectively, by coupling two individual transformer-based resonators (see Fig. 9.2.1). Apart from the large area penalty, the former needs an extra third winding (L_T) in each transformer that degrades the tank Q, while the latter used large, fixed coupling capacitors (C_M) that load the tank in two of the resonant modes, thus limiting the VCO FTR., QCD/Sebastiano Lab, QuTech, Quantum Circuit Architectures and Technology, Electronics

We demonstrate a 36 × 36 gate electrode crossbar that supports 648 narrow-channel field effect transistors (FET) for gate-defined quantum dots, with a quadratic increase in quantum dot count upon a linear increase in control lines. The crossbar is fabricated on an industrial 28Si-MOS stack and shows 100% FET yield at cryogenic temperature. We observe a decreasing threshold voltage for wider channel devices and obtain a normal distribution of pinch-off voltages for nominally identical tunnel barriers probed over 1296 gate crossings. Macroscopically across the crossbar, we measure an average pinch-off of 1.17 V with a standard deviation of 46.8 mV, while local differences within each unit cell indicate a standard deviation of 23.1 mV. These disorder potential landscape variations translate to 1.2 and 0.6 times the measured quantum dot charging energy, respectively. Such metrics provide means for material and device optimization and serve as guidelines in the design of large-scale architectures for fault-tolerant semiconductor-based quantum computing., QCD/Scappucci Lab, QuTech, BUS/Quantum Delft, QCD/Sebastiano Lab, Quantum Circuit Architectures and Technology, QN/Veldhorst Lab

We demonstrate a 36 × 36 gate electrode crossbar that supports 648 narrow-channel field effect transistors (FET) for gate-defined quantum dots, with a quadratic increase in quantum dot count upon a linear increase in control lines. The crossbar is fabricated on an industrial 28Si-MOS stack and shows 100% FET yield at cryogenic temperature. We observe a decreasing threshold voltage for wider channel devices and obtain a normal distribution of pinch-off voltages for nominally identical tunnel barriers probed over 1296 gate crossings. Macroscopically across the crossbar, we measure an average pinch-off of 1.17 V with a standard deviation of 46.8 mV, while local differences within each unit cell indicate a standard deviation of 23.1 mV. These disorder potential landscape variations translate to 1.2 and 0.6 times the measured quantum dot charging energy, respectively. Such metrics provide means for material and device optimization and serve as guidelines in the design of large-scale architectures for fault-tolerant semiconductor-based quantum computing., QCD/Scappucci Lab, BUS/Quantum Delft, QCD/Sebastiano Lab, Quantum Circuit Architectures and Technology, QN/Veldhorst Lab

This paper presents a 15b cryo-CMOS DAC for multiplexed spin-qubit biasing implemented in a 22-nm FinFET process. The integrating-DAC architecture and the robust digitally-assisted high-voltage output stage enable a low power dissipation (157W) and small area (0.08mm2) independent of the number of biased qubits, and a 3V output range well beyond the nominal supply. This represents the first scalable solution for cryo-CMOS qubit biasing, which achieves a 1.8× better voltage resolution with a lower DNL over a 3× larger output range than the current state-of-the-art., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., QCD/Sebastiano Lab, Electronics, Quantum Circuit Architectures and Technology

LC VCOs with low phase noise (PN) and an octave frequency-tuning range (FTR) are required for multistandard communication devices, software-defined radios, and wireline data links. A viable popular approach is to exploit multicore mode-switching VCOs for two reasons: (1) their PN improves linearly by in-phase coupling of N identical VCOs; (2) the resonant-mode switching enhances the VCO FTR without degrading the tank quality factor (Q) as no RF current ideally flows through lossy mode-selection switches. However, it is still challenging for dual-mode VCOs to achieve a competitive FoM while covering an octave FTR at oscillation frequencies (F_OSC) above 6GHz [1]. To enhance the number of oscillation modes to 3, [2] added a center-loop inductor (L_C) to a transformer, as shown in Fig. 9.2.1. However, a large FTR gap is measured, since the transformer windings should be strongly coupled to accommodate L_C, The authors of [3] and [4] realized a triple- and quad-mode operation, respectively, by coupling two individual transformer-based resonators (see Fig. 9.2.1). Apart from the large area penalty, the former needs an extra third winding (L_T) in each transformer that degrades the tank Q, while the latter used large, fixed coupling capacitors (C_M) that load the tank in two of the resonant modes, thus limiting the VCO FTR., QCD/Sebastiano Lab, Quantum Circuit Architectures and Technology, Electronics

Cryogenic CMOS (cryo-CMOS) is a viable technology for the control interface of the large-scale quantum computers able to address non-trivial problems. In this paper, we demonstrate state-of-the-art cryo-CMOS circuits and systems for such application and we discuss the challenges still to be faced on the path towards practical quantum computers., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., QuTech, Quantum Circuit Architectures and Technology, QCD/Sebastiano Lab, QCD/Vandersypen Lab, QCD/Almudever Lab, QCD/Scappucci Lab, QCD/Veldhorst Lab, QN/Vandersypen Lab, (OLD)Applied Quantum Architectures, Electronics

Cryogenic CMOS (cryo-CMOS) is a viable technology for the control interface of the large-scale quantum computers able to address non-trivial problems. In this paper, we demonstrate state-of-the-art cryo-CMOS circuits and systems for such application and we discuss the challenges still to be faced on the path towards practical quantum computers., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Quantum Circuit Architectures and Technology, QCD/Sebastiano Lab, QCD/Vandersypen Lab, QCD/Almudever Lab, QCD/Scappucci Lab, QCD/Veldhorst Lab, QN/Vandersypen Lab, (OLD)Applied Quantum Architectures, Electronics

In the summer of 2016, a solar-powered charging station for e-bikes (both wired and wireless) and e-scooters will be built on the campus of Delft University of Technology. This station is also meant to provide a testing facility for future projects. The station has a number of systems that generate data: the power electronics (including the solar panels, batteries and grid-connection), a weather station, solar panel temperature sensors and the connected vehicles. The SUNRISE (Smart Unified Networking Rig for an Integrated Solar E-bike charger) project is a BSc final project that should log and display all this data through an administrator page, a website and a local display. It should also be able to manage e-bike users that would like to connect to the station. Team ODROID was responsible for the local data management and charger control. The team managed to fetch all necessary data from the power electronics, temperature probes and weather station with C-code running on an ODROID C1+. Furthermore, the developed system was designed from the start to be robust (since it will be running 24/7) and has been thoroughly tested for possible malfunctions. The system has also been made resistant against power and internet outages. Moreover, the system can register e-bike cable connections, which it uses to fully control the chargers. It also provides data necessary to display system information on a local display. Finally, the entire system is remotely controllable through a remote desktop., Electrical Engineering, Mathematics and Computer Science, Electrical Sustainable Energy, DC Systems, Energy Conversion & Storage, EE3L11

In the summer of 2016, a solar-powered charging station for e-bikes (both wired and wireless) and e-scooters will be built on the campus of Delft University of Technology. This station is also meant to provide a testing facility for future projects. The station has a number of systems that generate data: the power electronics (including the solar panels, batteries and grid-connection), a weather station, solar panel temperature sensors and the connected vehicles. The SUNRISE (Smart Unified Networking Rig for an Integrated Solar E-bike charger) project is a BSc final project that should log and display all this data through an administrator page, a website and a local display. It should also be able to manage e-bike users that would like to connect to the station. Team ODROID was responsible for the local data management and charger control. The team managed to fetch all necessary data from the power electronics, temperature probes and weather station with C-code running on an ODROID C1+. Furthermore, the developed system was designed from the start to be robust (since it will be running 24/7) and has been thoroughly tested for possible malfunctions. The system has also been made resistant against power and internet outages. Moreover, the system can register e-bike cable connections, which it uses to fully control the chargers. It also provides data necessary to display system information on a local display. Finally, the entire system is remotely controllable through a remote desktop., Electrical Engineering, Mathematics and Computer Science, Electrical Sustainable Energy, DC Systems, Energy Conversion & Storage, EE3L11