Phd: Cryogenic Cmos-oxram Neuromorphic Circuits

**Context**:The latest major breakthrough in quantum computing (QC) has been the demonstration of quantum systems with more than 50 superconducting qubits allowing quantum supremacy for the first time. Other very promising qubit technologies include spin qubits based on solid-state quantum dots (QDs). They leverage the great maturity of CMOS technologies to offer low cost and highly scalable quantum devices. Major research centers like CEA, QuTech and Intel have started to report high quality spin qubits based on advanced CMOS technologies. However, the tuning and control of QDs are still performed mostly by hand with bulky classical electronics located outside the cryostat. The absence of fully integrated cryo-electronics capable of automatically tuning the QDs makes it currently impossible to build a large-scale quantum computer due to the “wiring bottleneck” between the quantum devices and the control electronics. In that scope, a 3IT-1QBit consortium composed of 10 world-class researchers and engineers in Canada is starting an ambitious research program to develop innovative solutions to that problem. We propose a PhD project to investigate cryogenic-compatible neuromorphic circuits based on TiO2 memristors (i.e. OxRAM) and CMOS circuits interconnected with superconducting materials. This CMOS-OxRAM chip will allow to implement automatic calibration methods of QDs using low power neural networks directly implemented into the cryostat.

**Project**:In collaboration with 2 postdoc fellows, 2 PhD students and 1 Master’s student, the PhD student recruited will be in charge of the fabrication of CMOS-OxRAM circuits with superconducting interconnects and the demonstration of in-memory computing in cryogenic conditions. This project will build upon the work of Pr. Dominique Drouin’s group at 3IT on TiO2-based memristors and QD auto-tuning using neural networks:

- Fully CMOS-compatible passive TiO2-based memristor crossbars for in-memory computing - ScienceDirect
- Investigation of resistive switching and transport mechanisms of Al2O3/TiO2−x memristors under cryogenic conditions (1.5 K): AIP Advances: Vol 10, No 2 (scitation.org)
- Miniaturizing neural networks for charge state autotuning in quantum dots - IOPscience

Supported by the expertise of 3IT, 1QBit and IQ in the fields of nanofabrication, neuromorphic engineering and cryogenic electronics, the student will have to (i) fabricate crossbar arrays of TiO2-based memristors on top of CMOS circuits with newly developed superconducting interconnects, (ii) perform the physico-chemical and morphological characterisations of the CMOS-OxRAM circuits to validate their quality, (iii) conduct in-depth electrical characterizations of the CMOS-OxRAM circuits at room and cryogenic temperatures in the Quantum Fab Lab of the IQ of UdeS, (iv) Investigate the benefits of using superconducting interconnects with regards to OxRAM switching behavior and programing precision, (v) demonstrate in-memory computing with an 8×8 OxRAM crossbar array at room and cryogenic temperatures and compare obtained accuracies.

**Supervision and work environment**:The thesis will be realized under the direction of Pr. Dominique Drouin and Pr. Serge Ecoffey within the IRL-LN2, an International Research Laboratory of the French CNRS based in Sherbrooke (QC, Canada). Pr. Fabien Alibart and Pr. Yann Beilliard will also participate in the supervision. The work will be carried out mainly at the Interdisciplinary Institute for Technological Innovation (3IT) and at the Quantum Institute (IQ) of UdeS, in close collaboration with the company 1QBit. 3IT is a unique institute in Canada, specializing in the research and development of innovative technologies for energy, electronics, robotics and health. The IQ is a state-of-the-art institute whose mission is to invent the quantum technologies of tomorrow and transfer them to the industry. 1QBit is a Canadian leader in QC, AI and high-performance computing. Its multidisciplinary team designs control systems, compilers and service architectures for exotic and next generation computing platforms. The student will thus benefit from an exceptional research environment that combines students, professionals, professors and industrialists working hand-in-hand to develop the future technologies for AI and QC.

**Desired profile**:

- Specialisation in micro-nanotechnologies, nanoscience or microelectronic engineering
- Skills in materials science, microfabrication in clean room and electrical characterization
- Leadership, curiosity, autonomy, sense of responsibility and teamwork
- Assets: Knowledge in design of integrated circuits and semiconductor devices

**Important information**:

- Starting date: as soon as possible

**Salary**: From $30,000.00 per year

Schedule:

- Monday to Friday

**Education**:

- Master's Degree (required)

Work Location: In person