We propose a measurement scheme to directly detect odd-frequency superconductivity via time- and angle-resolved photoelectron fluctuation spectroscopy. The scheme includes two consecutive, non-overlapping probe pulses applied to a superconducting sample. The photoemitted electrons are collected in a momentum-resolved fashion. Correlations between signals with opposite momenta are analyzed. Remarkably, these correlations are directly proportional to the absolute square of the time-ordered anomalous Greens function of the superconductor. This setup allows for the direct detection of the hidden order parameter of odd-frequency pairing. We illustrate this general scheme by concretely analyzing the signal for the prototypical case of two-band superconductors, which are known to exhibit odd-frequency pairing under certain conditions.
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