[1Ca02-12] SS1

[1Ca09S] Transport properties of monolayer FeSe on Nb-doped SrTiO₃ substrate

*Koshiro Ide¹, Toshihiro Kobayashi¹, Tomoaki Tanaka¹, Satoru Ichinokura¹, Ryota Shimizu², Taro Hitosugi², Toru Hirahara¹ (1. School of Science, Tokyo Institute of Technology, 2. School of Materials and Chemical Technology, Tokyo Institute of Technology)

We have been investigated superconductivity in the monolayer FeSe on the SrTiO₃ substrate by means of in situ four-point probe electrical transport measurements. In this study, we changed the substrate from undoped to Nb-doped SrTiO₃, which is expected to induce a superconducting transition to the FeSe at a higher temperature. Due to the parallel conductivity through the Nb-doped SrTiO₃, the superconducting transition is likely to appear as a small resistance change on the order of mΩ. Accordingly, we improved the accuracy of temperature control and resistance measurements. We demonstrate the improvement by showing the superconductivity in Nb thin films, followed by the results on the temperature-dependent sheet resistance and the I-V characteristics of the monolayer FeSe on the Nb-doped SrTiO₃.