Fundamental limits of Spectroscopy with Quantum Light

Z. Ficek, R. Tanaś

Francesco Albarelli, Evangelia Bisketzi, Aiman Khan +1 more

In order to rigorously find the limit of estimation precision for an atom probed by a quantum light pulse, the authors incorporate tools from quantum metrology and atomic spectroscopy. Their methodology uses a Hamiltonian model of the light-matter interaction to compute the information in the quantum state of the light after interaction with the atom.

Frank Schlawin

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.

Richard E. Slusher, S. L. McCall, A. Mysyrowicz +2 more

Zavatta A., Valentina Parigi, Bellini M.

Korenobu Matsuzaki, Tahei Tahara

Quantum light, such as entangled photon pairs, is a special state of light that cannot be described by classical electrodynamics. Owing to its exotic nonclassical properties, the use of quantum light can open up a new possibility for spectroscopy that cannot be realized by a classical light source. Recently, using entangled photon pairs as the light source, we demonstrated ultrasensitive absorption spectroscopy with quantum-enhanced sensitivity [1]. This novel approach allows us to obtain absorption spectra with a noise level suppressed below the shot-noise limit, which is a fundamental and unavoidable limit in conventional absorption spectroscopy. In this presentation, we will discuss two applications of this sub-shot-noise absorption spectroscopy.