Towards the Development of Cryogenic Integrated Power Management Units

Integrated Circuits (ICs) in cryogenic environments are expected to allow the development of scalable quantum computers consisting of thousands of physical quantum bits (qubits). However, since these ICs require undistorted power supply for optimal performance, the development of Power Management Units (PMUs) capable of cryogenic operation is also needed for the quantum computing systems scalability. To develop such PMUs, it is necessary to understand the cryogenic electrical behavior of its components. Therefore, this talk will present the measurement results obtained from an exploratory cryogenic DC characterization of some of the passive and active components belonging to a commercial 22nm FDSOI IC technology

Reconstitución de prácticas sociales de modelación: lo lineal a partir de análisis químicos. El caso de la curva de calibración

Una preocupación que compartimos es que el aprendizaje de las matemáticas se vive de manera descontextualizada. Desde construir matemáticas nos desplazamos a contribuir a formar profesionales, constituyendo una matemática relevante. Este trabajo se realiza en la comunidad de ingenieros bioquímicos y tiene como objetivo estudiar la práctica espectrofotométrica: curva de calibración en la escuela y en un laboratorio de investigación desde un enfoque socioepistemológico. El análisis de las formas en que se ejerce la práctica espectrofotométrica se llevó a cabo considerando las dimensiones: procedimientos, intenciones, herramientas y argumentos de quienes la ejercen. Estas dimensiones se evidencian por las formas en que quien ejerce la práctica, articula el modelo con lo modelado, configurando un dipolo modélico. Vía la deconstrucción como acercamiento metodológico, se caracteriza la práctica para la elaboración de un diseño de aprendizaje. En la aplicación de este diseño se muestra el actuar de los estudiantes en la construcción de la curva de calibración, se muestran evidencias de cómo los estudiantes identifican primeramente la necesidad de ajustar linealmente los datos, articulando el modelo gráfico, logrando además diversas formas de predicción usando la regla de tres y el modelo algebraico. El estudiante descentró un dipolo constituido basado en procesos algorítmicos incorporando un nuevo dipolo basado en el análisis de los datos experimentales. Robusteció su forma de interpretar resultados en la práctica espectrofotométrica, reconstituyendo así su práctica

Reconstitución de prácticas sociales de modelación: lo lineal a partir de análisis químicos. El caso de la curva de calibración

Our main concern is that the learning of mathematics could be experienced out of context. Because of this, we move from building the math foundations of our undergraduate students to their technical preparation; by this way, we establish a relevant math background in them. This work was developed inside the biochemical engineers’ community and it studies the technical practice of the spectrophotometry with emphasis in the calibration curve topic. The analysis of the ways in which the practice of the spectrophotometry is done was made under the consideration of the next dimensions: procedures, intentions, tools and the arguments of the ones who used them. This dimensions are uncover by the way in which the one who apply the practice of the spectrophotometry ties together the mathematical model of the physical phenomenon with the model obtained in the practice; the consequence is the setting of a model dipole. It is through the use of deconstruction, as an approximation method, that the practice of spectrophotometry has been characterized with the objective to elaborate a learning design. By applying this learning design, the acting of the students in the construction of the calibration curve is shown as well as the evidences of how they identify the necessity to adjust the data in a linear manner articulating a graphical model, obtaining different ways of prediction by using the three rules, the algebraic model or the graphical one. It is in this way that the student can achieve a strengthening of his interpretation of the practice of the spectrophotometry, reconstructing its practice.Una preocupación que compartimos es que el aprendizaje de las matemáticas se vive de manera descontextualizada. Desde construir matemáticas nos desplazamos a contribuir a formar profesionales, constituyendo una matemática relevante. Este trabajo se realiza en la comunidad de ingenieros bioquímicos y tiene como objetivo estudiar la práctica espectrofotométrica: curva de calibración en la escuela y en un laboratorio de investigación desde un enfoque socioepistemológico. El análisis de las formas en que se ejerce la práctica espectrofotométrica se llevó a cabo considerando las dimensiones: procedimientos, intenciones, herramientas y argumentos de quienes la ejercen. Estas dimensiones se evidencian por las formas en que quien ejerce la práctica, articula el modelo con lo modelado, configurando un dipolo modélico. Vía la deconstrucción como acercamiento metodológico, se caracteriza la práctica para la elaboración de un diseño de aprendizaje. En la aplicación de este diseño se muestra el actuar de los estudiantes en la construcción de la curva de calibración, se muestran evidencias de cómo los estudiantes identifican primeramente la necesidad de ajustar linealmente los datos, articulando el modelo gráfico, logrando además diversas formas de predicción usando la regla de tres y el modelo algebraico. El estudiante descentró un dipolo constituido basado en procesos algorítmicos incorporando un nuevo dipolo basado en el análisis de los datos experimentales. Robusteció su forma de interpretar resultados en la práctica espectrofotométrica, reconstituyendo así su práctica

Design and Cryogenic Characterization of Integrated Circuits for Quantum Computing

High performance Integrated Circuits (ICs) are a fundamental part of future Quantum Computers (QCs). The ICs of QCs need regulated, stable and noise free supply voltages. Supply voltage lines in dilution fridges are prone to voltage ripple noise due to pulse tube vibrations, ground loops induce noise and dynamic load currents. Cryogenic ICs for in situ voltage regulation can provide a clean voltage supply for the ICs of QCs. A voltage reference and a voltage regulator are presented as building blocks for cryogenic voltage regulation. The investigated circuits were developed in 22 nm FDSOI technology and tested from 6 K to 300 K

Cryogenic CMOS for Local Qubit Control and Readout – A Path to Scaling

The majority of the scientific research community for quantum computing agrees that an estimated number of around 106 qubits are required to build a universal quantum computer [1]. This number leads to foreseeable connectivity bottlenecks to feed all the required biasing, control and read-out signals into and out of the cryostat. A proposed solution is local cryogenic classical electronics, bringing control and read-out closer to the quantum bits themselves.For this task, the ZEA-2 – Electronic Systems institute – develops classical electronic systems using modern CMOS technologies, due to their low area footprint, ultra-low power consumption and natural synergy with semiconductor qubits. This poster highlights the ongoing development and measurement results at ZEA-2 for integrated cryogenic circuits and co-integrating them directly with qubits. This includes experimental results of a qubit bias voltage digital-to-analog converter (Bias-DAC) in a bulk 65 nm CMOS technology [2], placed at the milli-Kelvin stage alongside the qubit [3,4]. Results of cryogenic supply regulation circuits in an advanced 22nm FDSOI CMOS process are shown as well [5]. Furthermore, a brief introduction into CMOS and possible options for an optimized cryogenic specific CMOS technology is given to enhance future IC designs in power efficiency and outlook to qubit readout. This method of integration paves a way for QC scalability.[1] Vandersypen, L.M.K., Bluhm, H., Clarke, J.S. et al. Interfacing spin qubits in quantum dots and donors—hot, dense, and coherent. npj Quantum Inf 3, 34 (2017). https://doi.org/10.1038/s41534-017-0038-y[2] P. Vliex et al., "Bias Voltage DAC Operating at Cryogenic Temperatures for Solid-State Qubit Applications," in IEEE Solid-State Circuits Letters, vol. 3, pp. 218-221, 2020, doi: 10.1109/LSSC.2020.3011576.[3] R. Otten, L. Schreckenberg, P. Vliex et al., "Qubit Bias using a CMOS DAC at mK Temperatures," 2022 29th IEEE International Conference on Electronics, Circuits and Systems (ICECS), Glasgow, United Kingdom, 2022, pp. 1-4, doi: 10.1109/ICECS202256217.2022.9971043. [4] L. Schreckenberg, R. Otten, P. Vliex et al., "SiGe Qubit Biasing with a Cryogenic CMOS DAC at mK Temperature„ To be published in 2023 49th IEEE European Conference on Solid-State Circuits (ESSCIRC)[5] A. R. Cabrera-Galicia, A. Ashok, P. Vliex et al., "Towards the Development of Cryogenic Integrated Power Management Units," 2022 IEEE 15th Workshop on Low Temperature Electronics (WOLTE), Matera, Italy, 2022, pp. 1-4, doi: 10.1109/WOLTE55422.2022.9882781

Towards the Development of Cryogenic Integrated Power Management Units

Integrated Circuits (ICs) operating at cryogenic temperatures are expected to allow the development of scalable quantum computing systems consisting of thousands of physical quantum bits (qubits). However, since these ICs require undistorted power supply lines for optimal performance, the development of Power Management Units (PMUs) capable of cryogenic operation is also needed for the quantum computing systems scalability. To develop such PMUs, it is necessary to understand the cryogenic electrical behavior of its components. Therefore, this brief present the measurement results obtained from an exploratory cryogenic DC characterization of some of the passive and active components belonging to a commercial 22nm FDSOI IC technology

Design of Power Efficient Digital Low-Dropout Circuit for Quantum Computers

Quantum computing is an approach to enable new computing paradigms with qubits as the computing elements that require individual tuning. A limitation in current setups is the number of controllable qubits. To scale the number of qubits, a close integration of control circuits close to the qubits in the cryogenic environment is required. However, to deal with these cryostats* minimal thermal power budget, ultra-low power dissipation is required, also for biasing circuits.This contribution presents the design and simulation results of a power-efficient digital low-dropout regulator developed with a commercial 22nm FDSOI technology. It is expected that the circuit will enable on-chip biasing for future quantum computers based on Cryogenic Electronics operating at 4 K. Unlike its Analog counterpart integrated Digital LDO is not prone to process and mismatches delivering high efficiency at the same time The circuit concept and the system model investigation performed via Matlab-Simulink will be showed, as well as the expected circuit performance

Self-Heating Effect in a 65 nm MOSFET at Cryogenic Temperatures

We characterized the thermal behavior of a 65 nm bulk CMOS transistor, by measuring the self-heating effect (SHE) as a function of bias condition. We demonstrated that at a base temperature of 6.5 K the channel temperature of the transistor can increase up to several tens of kelvins due to power dissipation. The thermal behavior of the transistor is determined not only by the thermal response of the transistor itself but also by the thermal properties of the surroundings, i.e., source, drain, bulk, and gate interfaces, metal contacts, and vias. On top of it, the thermal response is bias-dependent through bias dependence of power and self-heating. This information becomes relevant for proper design of integrated circuits for quantum computing or other cryogenic applications, where the circuitry requires to be operated at a stable cryogenic temperature

Power Integrity Challenges in Large Scale Quantum Computers and Solutions

The ICs belonging to a quantum computer need stable and regulated supply voltages for proper operation, e.g. the phase noise of RF oscillators is dependent on their power supply quality. Moreover, the power supply needs of a large scale QC will be challenging to satisfy by simply using supply lines connecting the ICs inside the cryostat with the power sources at room temperature. This is because voltage ripples (e.g. pulse tube vibration induced noise), ground loops induced noise and dynamic load currents may affect the ICs supply lines and compromise the QC power integrity. Furthermore, it is expected that the connection lines available in large scale QCs be scarce due to the limited cryostat space. Therefore, the usage of several lines to set different supply domains may not be possible and be a restricting factor for the QCs scalability.This presentation will address the cryogenic power integrity topic by providing:— A review of the power integrity challenges faced by cryogenic ICs. — Solution approaches focused on the cryogenic setup and the use of cryogenic voltage regulators. — Cryogenic characterization and modelling of FDSOI technology (22 nm) for ICs design. — Design and test of cryogenic voltage references, based on cryogenic Vth saturation and Vth difference. — Design and test of a cryogenic voltage regulator. — Design of Digital LDOs for cryogenic applications. — An application case: cryogenic voltage regulator applied to power the reference circuit of a cryogenic DAC used for the DC voltage setting of a Single Electron Transistor Quantum Do