Surface Current and DC Cross Talk in Superconducting Quantum Devices

Unwanted electromagnetic interference between qubits, transmission lines, flux lines and other elements of a superconducting quantum processor poses a challenge in engineering such devices. This problem is exacerbated with scaling up the number of qubits. High fidelity, massively parallel computational toolkits, which can simulate the 3D electromagnetic environment and all features of the device, are instrumental in addressing this challenge. While RF crosstalk has to some extent been studied, DC crosstalk remains an intriguing topic to address. In this work, we investigated the DC surface current on a superconducting chip and crosstalk between various elements of a multi-qubit superconducting quantum processor. The simulations are carried out with a high fidelity, massively parallel EM solver developed at Anyon Systems. We will present our findings regarding the sources of crosstalk in the device, design guidlines, as well as numerical model setup.