Quantumness from ultrafast spectroscopy experiments*

The role of quantumness in the energy transfer process in light-harvesting complexes has long been debated. A major obstacle in verifying competing hypothesis is the complicated nature of ultrafast spectroscopy experiments. While multidimensional ultrafast optical spectroscopy has been crucial in clarifying the nature of interacting multi-chromophoric systems, the underlying mechanisms of energy transport in light-harvesting complexes remain unclear. Earlier works have shown that 2D electronic spectroscopy can provide enough information to perform quantum process tomography on the multi-chromophoric light-harvesting complexes. We build upon this methodology to provide more efficient spectroscopic techniques that can provide bounds of measures of quantumness. In particular, we show how the nature of quantum correlations can be extracted directly from measured data rather than hypothesized models. We expect our tools to be applicable to the evaluation of quantumness from other spectroscopy experiments or any other data stream in general.