Quantum physics with pulses of radiation*

The ability to control quantum systems and apply special superposition states and entangled states of light and matter is pursued with many experimental platforms and forms the basis of strategies for quantum computing, communication and metrology. I shall discuss the interaction of a quantum system with a pulse of quantized radiation. While crucial for multiple effects in quantum optics and for the entire concept of flying and stationary qubits, quantum optics textbooks do not provide a formal description of this foundational and elementary interaction process. I shall present a new (and simple) theoretical formalism [1] that accounts for the interaction of travelling pulses of quantized radiation with a local quantum system such as a qubit, a spin or a multi-level atom in a cavity. Applications of the theory are shown for recent experiments with optical, microwave and acoustic quantum pulses.

[1] Alexander Holm Kiilerich and Klaus Mølmer, Phys. Rev. Lett. 123, 123604 (2019).