Rabi profile framework: A simple analytical and graphical toolkit for quantum control

We introduce the Rabi profile, the Rabi spectrum, and the Rabi leak as triad of mathematically rigorous but conceptually transparent quantum-control tools that provide a framework for assessing the feasibility and selectivity of coherent state control in quantum systems with arbitrarily many levels, without recourse to numerical simulation. As the rigorous foundation for this framework, we present a self-contained discussion of the rotating wave approximation (RWA) and its limits, suitable for use as classroom material. We illustrate its practical utility by application to design of superconducting transmon qubits. Because it reduces complex quantum control questions to elementary frequency-domain reasoning, the Rabi profile framework is intended to serve equally as a research diagnostic and as a pedagogical bridge between introductory quantum mechanics and contemporary quantum technologies.