Principles of Phase Coherence in Multi-Channel Quantum Control Architectures

Executing multi-qubit quantum circuits with high fidelity requires maintaining a high level of phase coherence between all qubit drive channels. In this talk, we show how fluctuations in the relative phase of drive channels affect two-qubit gate fidelities and then discuss how to measure and quantify relative phase coherence. Finally, we consider the relative phase coherence of different signal generation architectures that are used in practice.