Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague 2, Czech Republic.
Nat Commun. 2013;4:1422. doi: 10.1038/ncomms2426.
(Ga,Mn)As is at the forefront of spintronics research exploring the synergy of ferromagnetism with the physics and the technology of semiconductors. However, the electronic structure of this model spintronics material has been debated and the systematic and reproducible control of the basic micromagnetic parameters and semiconducting doping trends has not been established. Here we show that seemingly small departures from the individually optimized synthesis protocols yield non-systematic doping trends, extrinsic charge and moment compensation, and inhomogeneities that conceal intrinsic properties of (Ga,Mn)As. On the other hand, we demonstrate reproducible, well controlled and microscopically understood semiconducting doping trends and micromagnetic parameters in our series of carefully optimized epilayers. Hand-in-hand with the optimization of the material synthesis, we have developed experimental capabilities based on the magneto-optical pump-and-probe method that allowed us to simultaneously determine the magnetic anisotropy, Gilbert damping and spin stiffness constants from one consistent set of measured data.
(Ga,Mn)As 是自旋电子学研究的前沿领域，探索了铁磁性与半导体物理和技术的协同作用。然而，这种模型自旋电子材料的电子结构一直存在争议，并且基本的微磁参数和半导体掺杂趋势的系统和可重复的控制尚未建立。在这里，我们表明，看似微小的偏离单独优化的合成方案会导致非系统的掺杂趋势、本征电荷和磁矩补偿以及掩盖 (Ga,Mn)As 固有特性的非均匀性。另一方面，我们在一系列经过精心优化的外延层中证明了可重复、良好控制和微观理解的半导体掺杂趋势和微磁参数。随着材料合成的优化，我们开发了基于磁光泵浦和探测方法的实验能力，使我们能够从一组一致的测量数据中同时确定磁各向异性、吉尔伯特阻尼和自旋弹性常数。
