Speaker: Eduardo da Silva Neto (Yale University)

Host: Tom Iadecola

Title: Nematicity, Superconductivity and Broken Symmetries in Fe-based Materials

Abstract: Unconventional superconductivity in Fe-based materials has been studied for more than 15 years. Electronic nematicity, where rotational symmetry is broken, is s novel quantum state of matter proposed 25 years ago [Nature 393, 550 (1998)]. This phase has been shown to play an important role in the phase diagram of the Fe-based superconductors, as indicated by recent experiments that revealed the existence of nematic quantum criticality and strange metal behavior [e.g. Nature 567, 213-317 (2019)]. However, as summarized in a recent review [Nature Physics, 18, 1412 (2022)], how nematicity influences superconductivity and whether nematic fluctuations can create superconductivity on their own are crucial questions that have thus far remained unanswered. In this talk, I will delve into our recent experiments aimed at addressing this particular question. We have focused our studies on the intriguing FeSe_1-xS_x system via scanning tunneling spectroscopy measurements, complemented by photo-emission experiments and theoretical calculations.