[12p-M101-1~14] 10.4 半導体スピントロニクス・超伝導・強相関

▲ [12p-M101-9] Electronic structure of p-type ferromagnetic semiconductor (Ga,Fe)Sb: Valence band and impurity band

〇Takahito Takeda¹、Masahiro Suzuki²、Le Duc Anh^1,3、Yosuke Nonaka²、Thorsten Schmitt⁴、Satoshi Yoshida⁵、Masato Sakano⁵、Kyoko Ishizaka⁵、Yukiharu Takeda⁶、Shin-ichi Fujimori⁶、Munetoshi Seki^1,3、Hitoshi Tabata^1,3、Atsushi Fujimori²、Masaaki Tanaka^1,3、Vladimir N. Strocov⁴、Masaki Kobayashi^1,3 (1.Grad. Sch. Eng., Univ. of Tokyo、2.Dep. Phys., Univ. of Tokyo、3.CSRN, Univ. of Tokyo、4.Swiss Light Source、5.QPEC, Grad. Sch. Eng., Univ. of Tokyo、6.JAEA/SPring-8)

キーワード：Ferromagnetic semiconductor, Angle-resolved photoemission spectroscopy

Ferromagnetic semiconductors (FMSs) are alloy semiconductors in which cations are partially replaced by magnetic impurities. FMSs have both the properties of ferromagnets and semiconductors and exhibit carrier-induced ferromagnetism, thereby attracting much attention as promising materials for semiconductor spintronics devices because one can control their magnetic properties by changing the carrier concentration. However, the Curie temperature (T_C) of III-V based FMSs was much lower than room temperature (RT) despite tremendous efforts for the past two decades. Recently, Tu et al., have successfully grown p-type (Ga,Fe)Sb whose T_C is higher than RT. Magnetic circular dichroism (MCD), magnetotransport, and magnetization measurements indicate that (Ga,Fe)Sb is an intrinsic ferromagnetic semiconductor . In this study, we conducted soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES) measurements on (Ga_1-x,Fe_x)Sb with x = 0.05 and GaSb thin films to reveal the band structure and to unveil the origin for the high-T_C ferromagnetism above RT.