Ricerc@Sapienza

Historically originated in the 1660s through the study of visible light dispersed by a prism according to its wavelength, spectroscopy has evolved into the prime matter investigation technique, sprouting an uncountable amount of experimental realizations of increasing complexity, based on non-linear couplings of an electromagnetic field with atomic and molecular systems. Conventional nonlinear spectroscopy uses classical light to detect matter properties through the variation of its response with frequencies and time delays among complex pulses sequences.
Quantum optics studies those properties of light which cannot be described by classical electromagnetic theory. Among them, the strong photon correlations enabled by quantum mechanics known as quantum entanglement, which have been proven to be critical in diverse areas, ranging from secure quantum communication, computing and metrology. These two disciplines are, to date, distinct branches of photonics, with different communities and objectives. Very recently, however, visionary theoretical work suggested implications of quantum optics for spectroscopy. Building on the complementary expertise of the team members in the fields of quantum optics, spectroscopy and biochemistry, here we propose the experimental realization of a spectroscopic set up, exquisitely conceived to exploit the properties of entangled photons to prepare and interrogate out-of-equilibrium states of matter, free from the ties imposed by the Heisenberg principle. Specifically, we will develop an efficient source of entangled photon pairs, which will be used to perform two-photon absorption with unprecedented energy selectivity and efficiency. Entangling the photons will be the key to disentangle system dynamics, which otherwise would be obscured by the constrained time-energy distributions of individual particles. This will enable conveying energy into molecular reaction centres throughout manifolds of complex pathways in an orchestrated way.