Hadas Soifer

Congratulations to Hadas Soifer, Zuckerman Faculty Scholar at Tel Aviv University’s School of Physics and Astronomy, on the publication of her study, “Trion gas on the surface of a failed excitonic insulator,”  in the November 28 issue of arXiv. The study explores systems that convert energy into motion and self-organize into complex patterns.

Abstract:
Trions, three-body bound states composed of an exciton and an additional charge, are typically fragile and require external excitation to form. Here, we report the spontaneous emergence of a stable trion gas at the surface of the layered semiconductor Ta2NiS5, revealed through angle-resolved photoemission spectroscopy. We observe a sharp, highly localized in-gap feature that cannot be explained by conventional band-theory. Instead, we argue that it arises from the formation of negative trions, stabilized by surface-induced band bending and the material’s quasi-one-dimensional geometry.