Dilute magnetic semiconductors (DMS) are nonmagnetic semiconductors doped with magnetic transition metals. The recently discovered DMS material (${\mathrm{Ba}}_{1-x}{\mathrm{K}}_x){\left({\mathrm{Zn}}_{1-y}{\mathrm{Mn}}_y\right)}_2{\mathrm{As}}_2$ offers a unique and versatile control of the Curie temperature $T_{\mathrm{C}}$ by decoupling the spin (${\mathrm{Mn}}^{2+}$, $S=5/2$) and charge (${\mathrm{K}}^{+}$) doping in different crystallographic layers. In an attempt to describe from first-principles calculations the role of hole doping in stabilizing ferromagnetic order, it was recently suggested that the antiferromagnetic exchange coupling $J$ between the nearest-neighbor Mn ions would experience a nearly twofold suppression upon doping 20% of holes by potassium substitution. At the same time, further-neighbor interactions become increasingly ferromagnetic upon doping, leading to a rapid increase of $T_{\mathrm{C}}$. Using inelastic neutron scattering, we have observed a localized magnetic excitation at about 13 meV associated with the destruction of the nearest-neighbor Mn-Mn singlet ground state. Hole doping results in a notable broadening of this peak, evidencing significant particle-hole damping, but with only a minor change in the peak position. We argue that this unexpected result can be explained by a combined effect of superexchange and double-exchange interactions.

中文翻译：

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（Ba1-xKx）（Zn1-yMny）2As2中最近的Mn2 +自旋之间反铁磁耦合的弱掺杂依赖性

稀磁性半导体（DMS）是掺杂有磁性过渡金属的非磁性半导体。最近发现的DMS材料（${巴}_{\mathrm{1个}-X}{\mathrm{ķ}}_X）{（{锌}_{\mathrm{1个}-ÿ}{锰}_{ÿ}）}_{\mathrm{2个}}{\mathrm{作为}}_{\mathrm{2个}}$ 提供独特且通用的居里温度控制 ${Ť}_{\mathrm{C}}$ 通过解耦自旋（${锰}^{\mathrm{2个}+}$， $\mathrm{小号}=5/\mathrm{2个}$）并收费（${\mathrm{ķ}}^{+}$）在不同的晶体学层中掺杂。为了尝试从第一性原理计算来描述空穴掺杂在稳定铁磁序中的作用，最近有人提出反铁磁交换耦合$Ĵ$通过钾取代对20％的空穴进行掺杂后，最接近的Mn离子之间的Mn离子将受到几乎两倍的抑制。同时，在掺杂时，相邻元素之间的铁磁性越来越强，从而导致铁氧体的快速增加。${Ť}_{\mathrm{C}}$。使用非弹性中子散射，我们已经观察到了与最邻近的Mn-Mn单线态基态的破坏相关的约13 meV的局部磁激发。空穴掺杂导致该峰显着变宽，表明明显的颗粒-空穴阻尼，但峰位置仅有很小的变化。我们认为，这种意外结果可以用超级交换和双重交换交互作用的组合效应来解释。