The strontium ruthenate mounted on a copper puck for electron spectroscopy. A Serendipitous Signal in Strontium RuthenateThe Illinois team was not looking for Pines’ demon when they found it. The detection was replicated across five separate measurements from four different strontium ruthenate crystals, ruling out a measurement artifact. What the Discovery Suggests About Multiband MetalsThe conditions that allow a demon to form are not unique to strontium ruthenate. Earlier spectroscopy studies of strontium ruthenate had missed the demon entirely because their momentum resolution was too coarse.