[1P01-52] Poster Presentation

[1P11] Effect of modifying with light elements on properties of a topological superconductor Fe(Se,Te)

*Shota Shimizu¹, Ryota Akiyama¹, Rei Hobara¹, Shuji Hasegawa¹ (1. Graduate School of Science, The University of Tokyo)

A topological superconductor (TSC) possesses superconductivity accompanied by a novel quantum state with a Majorana particle which is itself an antiparticle appearing on the surfaces or edges of the material. The typical TSC candidates are Cu_xBi₂Se₃ and Pb/TlBiSe₂, but the superconducting transition temperatures T_C are still low, 3.8 K and 10 K, respectively. Meanwhile, Fe(Se,Te), which has been reported as a TSC recently, has the highest T_C ~ 14 K. Moreover, thanks to a van der Waals material, it is expected that both intercalation of foreign atoms and molecules between the layers is possible besides adsorption on the surface. We cleaved Fe(Se,Te) crystal in a vacuum and modified it by hydrogen and/or alkali metals to enhance T_C by increasing Debye frequency and carrier density. We measured resistance in situ by independently driven four-probe STM, and the T_C increased from 10.2 K to 12.3 K by hydrogen exposure. We aim to further enhancement of T_C by optimizing conditions.