Our primary goal is to pioneer a groundbreaking approach for scalable qubit control and readout by harnessing the combined power of CMOS and superconducting circuits. At present, the quantum computing community faces a critical challenge in terms of scalability. Quantum systems relying on room temperature equipment can effectively handle approximately 100 qubits, however, the future demands for quantum computing power are projected to be exponentially larger, reaching the range of 1000 to 10000 qubits. The current methods simply lack the scalability required to meet this demand. This is where cryogenic-CMOS and superconducting circuits become a game-changer by offering easily scalable, low power, and low-cost qubit control and readout solutions.
By leveraging cryogenic-CMOS ICs, we aim to develop a control and readout system that can efficiently manage the significantly increased number of qubits needed for the next generation of quantum computers. One of recent work involves the demonstration of cryogenic CMOS receiver for multiplexed qubit readout.
Another notable challenge in the field involves the use of ferrite-based isolators and circulators inside dilution fridges. While effective in many respects, these components introduce a significant issue – they generate strong magnetic fields that may interfere with qubits and they occupy the valuable real-estate within the dilution refrigerator due to their bulky form factor. In this effort, we are exploring innovative spatiotemporal modulation methods to design and fabricate superconducting isolators and circulators without the use of ferrites, thereby aiming to replace the problematic ferrite-based devices. This approach holds tremendous potential in eliminating magnetic field interference, reducing form-factors, implementation cost while preserving the low loss signal routing and high isolation capabilities within the cryogenic system. By developing these advanced spatiotemporal modulation-based devices, we’re not only addressing the interference problem but also contributing significantly to the overall scalability and robustness of quantum computing platforms. One of our recent works involves the demonstration of a superconducting isolator based on coupled resonator systems.
Related Publications:
- A. Nagulu, L. M. Ranzani, G. J. Riebell, M. V. Gustafsson, T. A. Ohki and H. Krishnaswamy, “Sub-mW/qubit 5.2-7.2GHz 65nm Cryo-CMOS RX for Scalable Quantum Computing Applications,” 2023 IEEE Custom Integrated Circuits Conference (CICC), San Antonio, TX, USA, 2023, pp. 1-2, doi: 10.1109/CICC57935.2023.10121300.
- Y. Zhuang, C. Gaikwad, D. Kowsari, E. Henriksen, K. Murch and A. Nagulu, “Superconducting Non-reciprocal Bandpass Filter Based on Spatio-Temporal Inductance Modulation,” 2023 IEEE/MTT-S International Microwave Symposium – IMS 2023, San Diego, CA, USA, 2023, pp. 660-663, doi: 10.1109/IMS37964.2023.10188176.