[9p-Z27-1~24] 11.1 Fundamental properties

[9p-Z27-14] Composition dependence of penetration depth in Fe(Se,Te) films

〇Fuyuki Nabeshima¹, Hodaka Kurokawa¹, Sota Nakamura¹, Naoki Shikama¹, Yuki Sakishita¹, Tomoki Kobayashi¹, Yue Sun², Haruhisa Kitano², Atsutaka Maeda¹ (1.Univ. of Tokyo, 2.Aoyama Gakuin Univ.)

Keywords:iron-based superconductor, thin film, magnetic penetration depth

With increasing Te content, Fe(Se,Te) thin films shows drastic increase in T_c at the composition that the structural transition disappears. In this study, we measured magnetic penetration depth in Fe(Se,Te) thin films to investigate the origin of the increase of T_c in terms of the superfluid density. We observed T_c is proportional to λ(0)^-2 (∝ superfluid density) for all the samples in both the tetragonal and orthorhombic phases. The increase in T_c observed in Fe(Se,Te) originates from the increase of the superfluid density associated with the increase of the carrier density in the normal state.