Enduring relevance of the Jaynes–Cummings model: a personal perspective [Invited]

In this short perspective paper we present our personal highlights on how the Jaynes–Cummings model has become a central model to describe spin-boson couplings underpinning much of modern quantum optics. To the current authors, the key contribution is a demonstration of a measurable effect that showed the discreteness of the quantized radiation field.