Minority-spin impurity band in n-type (In,Fe)As: A materials perspective for ferromagnetic semiconductors
Minority-spin impurity band in n-type (In,Fe)As: A materials perspective for ferromagnetic semiconductors
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n 型 (In,Fe)As 中的少数自旋杂质能带：铁磁半导体的材料视角
DOI：
10.1103/physrevb.103.115111
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发表时间：
2021
影响因子：
3.7
通讯作者：
Strocov Vladimir N.
中科院分区：
文献类型：
--
作者：
Kobayashi Masaki;Anh Le Duc;Minar Jan;Khan Walayat;Borek Stephan;Hai Pham Nam;Harada Yoshihisa;Schmitt Thorsten;Oshima Masaharu;Fujimori Atsushi;Tanaka Masaaki;Strocov Vladimir N.
充分理解n型铁磁半导体(FMS)的性质是对主流类型FMS的补充，这是半导体自旋电子学的一个具有挑战性的目标，因为从理论上讲，FMS中的铁磁性是不平凡的。软X射线角分辨光电子能谱(SX-ARPES)是研究FMS中载流子感生铁磁性机制的有力手段。在这里，我们对原型FMS(In，Fe)As的SX-ARPES研究揭示了整个能带结构，包括Fe杂质带(IBS)和主体InAs带，并为InAs导带(CB)的电子占据提供了直接证据。少数自旋Fe-IB位于导带极小值(CBM)以下。未被占据的铁酸盐与被占据的InAs的CBM以自旋相关的方式杂化形成IB，从而导致CB的大自旋极化。含有IB的能带结构随着能带填充的不同而不同，这不能用刚性带图来解释，这表明在FMS材料中实现载流子感生铁磁性的图景是统一的。
Fully understanding the properties ofn-typeferromagnetic semiconductors (FMSs), complementary to the mainstream-type ones, is a challenging goal in semiconductor spintronics because ferromagnetism in-type FMSs is theoretically nontrivial. Soft-x-ray angle-resolved photoemission spectroscopy (SX-ARPES) is a powerful approach to examine the mechanism of carrier-induced ferromagnetism in FMSs. Here our SX-ARPES study on the prototypical-type FMS (In,Fe)As reveals the entire band structure, including the Fe-impurity bands (IBs) and the host InAs ones, and provides direct evidence for electron occupation of the InAs-derived conduction band (CB). A minority-spin Fe-IB is found to be located just below the conduction-band minimum (CBM). The IB is formed by the hybridization of the unoccupied Festates with the occupied CBM of InAs in a spin-dependent way, resulting in the large spin polarization of CB. The band structure with the IB is varied with band filling, which cannot be explained by the rigid-band picture, suggesting a unified picture for realization of carrier-induced ferromagnetism in FMS materials.