Quantum electrodynamics formulation of multidimensional spectroscopy

We present a description of multidimensional spectroscopy, where all the light pulses are treated quantum-mechanically and the signal is expressed as a quantum dynamical map of the broadband light fields. Focusing in particular on the rephasing contribution to two-dimensional spectroscopy, we demonstrate how the semiclassical description emerges naturally as a limiting case of the quantum description. Our work establishes a formalism to apply quantum information methods to the optimization of multidimensional spectroscopy and address, e.g., fundamental resolution limits from a quantum metrological perspective.