Quantum Electrodynamic Modeling of Superconducting Circuits

The demand for rapid and high-fidelity execution of initialization, gate and read-out operations casts tight constraints on the accuracy of quantum electrodynamic modeling of superconducting integrated circuits. Attaining the required accuracies requires reconsidering our basic approach to the quantization of the electromagnetic field in spatially inhomogeneous waveguides and the notion of normal modes. I will discuss a computational framework based on the Heisenberg-Langevin approach to address these fundamental questions. This framework allows the accurate determination of the quantum dynamics of a superconducting qubit in an arbitrarily complex electromagnetic environment infinite in extent, for any coupling strength and any degree of openness. This includes the regime of overlapping resonances and the "ultra-strong coupling" regime. I will also discuss the effectiveness of this computational approach in meeting the demands of present-day quantum computing research.

This work has been carried out with Moein Malekakhlagh, Alex T. Petrescu and Saeed Khan.