Field-Free Superconducting Diode Effect in Layered Superconductor FeSe
Utane Nagata, Motomi Aoki, Akito Daido, S. Kasahara, Y. Kasahara, Ryo Ohshima, Yuichiro Ando, Youichi Yanase, Yuji Matsuda, Masashi Shiraishi
Abstract
The superconducting diode effect (SDE), where zero-resistance states appear nonreciprocally during current injection, is receiving tremendous interest in both fundamental and applied physics because the SDE is a novel manifestation of symmetry breaking and enables the creation of a novel diode. In particular, magnetic-field-free SDEs have been extensively investigated because of their potential to serve as building blocks for superconducting circuit technology. In this Letter, we report the field-free SDE in a layered superconductor, FeSe. Its underlying physics is clarified by systematic controlled experiments to be an interplay of a large thermoelectric response and geometrical asymmetry in FeSe. Our findings can pave a new avenue for the construction of novel material and device platforms utilizing SDEs.