The goal of INCEPT project was to develop a new generation of time resolved spectroscopy combining quantum optic techniques with the traditional pump and probe approach, and thereby set the fundaments to use statistical properties of light in non-equilibrium spectroscopy. The leitmotiv of the action was the fact that light-matter interaction can imprint in the quantum state of probe pulses information on the transient response of the material which are not visible in mean value probe properties but can be retrieved by studying the full statistical properties of light. To this purpose, in INCEPT we implemented a combined theoretical and experimental action and delivered both the hardware to measure photonic fluctuation in time domain experiments, as well as the theoretical framework to understand which is the information carried by such fluctuations.
In contrast to standard optical techniques, which measure the probe pules after the interaction with the sample integrated over many repetitions, we developed different single shot detection schemes which allow for the measurements of the photon number fluctuations in probe pulses both frequency integrated and frequency-resolved. We implemented and used experiments combining non-equilibrium spectroscopy techniques and statistical characterization of the probe pulses. We developed means to exploit both classical fluctuations of laser pulses as well as the intrinsic fluctuations of quantum origin. In addition to the experimental development we have developed an effective theoretical framework to understand how fluctuations in materials are mapped onto measurable photonic fluctuations of probe properties.
INCEPT activities have been well timed with other efforts in the scientific community. Our fundamental research is across the research fields of material science and quantum information. As testified by various research programs from different funding agencies (Quantera flagship, EPSRC quantum technology program) one of the major technological and scientific challenges emerging in the last decade is understanding how we can harness the properties of quantum mechanics for technological purposes. In this context, the results obtained in INCEPT stand out as a paradigmatic change in the approach to non-equilibrium physics. This could have an impact on both our comprehension of quantum materials as well as in information technology. The positive outcome of the project activities carried out is testified by the high profile of our publications and a large number of invited contributions to the major conferences the team members received. Thanks also to INCEPT activities the non-equilibrium community is now recognizing the potential of combining non-equilibrium approaches with quantum information protocols for understanding and controlling the functionalities of complex quantum materials. Overall, the action has been successful and delivered the scientific fundaments of a possible new paradigm for non-equilibrium spectroscopies leveraging on photonic noise.
