Ultrafast, multidimensional spectroscopy unlocks macroscopic-scale effects of quantum electronic correlations. Researchers found that low-energy and high energy states are correlated in a layered, superconducting material. Exciting the material with an ultrafast beam of near-infrared light produces coherent excitations lasting a surprisingly ‘long’ time of around 500 femtoseconds, originating from a quantum superposition of excited states within the crystal.