Circuit Models For The Co-simulation of Superconducting Quantum Computing Systems

Rohith Acharya1,2, Fahd A. Mohiyaddin2, Anton Potočnik2, Kristiaan De Greve2, Bogdan Govoreanu2, Iuliana P. Radu2, Georges Gielen1,2 and Francky Catthoor1,2
1Department of Electrical Engineering (ESAT), KU Leuven, Kasteelpark Arenberg 10, Leuven, B-3001, Belgium
2Imec, Kapeldreef 75, Leuven, B-3001, Belgium


Quantum computers based on superconducting qubits have emerged as a leading candidate for a scalable quantum processor architecture. The core of a quantum processor consists of quantum devices that are manipulated using classical electronic circuits, which need to be co-designed for optimal performance and operation. As the principles governing the behavior of the classical circuits and the quantum devices are different, this presents a unique challenge in terms of the simulation, design and optimization of the joint system. A methodology is presented to transform the behavior of small-scale quantum processors to equivalent circuit models that are usable with classical circuits in a generic electrical simulator, enabling the detailed analysis of the impact of many important non-idealities. The methodology has specifically been employed to derive a circuit model of a superconducting qubit interacting with the quantized electromagnetic field of a superconducting resonator. Based on this technique, a comprehensive analysis of the qubit operation is performed, including the coherent control and readout of the qubit using electrical signals. Furthermore, the effect of several non-idealities in the system such as qubit relaxation, decoherence and leakage out of the computational subspace are captured, in contrast to previous works. As the presented method enables the co-simulation of the control electronics with the quantum system, it facilitates the design and optimization of near-term superconducting quantum processors.

Keywords: Quantum Computing, Control Electronics, Cosimulation, Equivalent Circuit Models, Qubit Readout, Qubit Control, Non-Idealities In Quantum Systems.

Full Text (PDF)