Title: Constraints on proximity-induced ferromagnetism in a Dirac semimetal (Cd$_3$As$_2$)/ferromagnetic semiconductor (Ga$_{1-x}$Mn$_x$Sb) heterostructure Show Chinese title

Title: 在狄拉克半金属（Cd$_3$As$_2$）/铁磁半导体（Ga$_{1-x}$Mn$_x$Sb）异质结构中对近邻诱导铁磁性的约束

Abstract: Breaking time-reversal symmetry in a Dirac semimetal Cd$_3$As$_2$ through doping with magnetic ions or by the magnetic proximity effect is expected to cause a transition to other topological phases (such as a Weyl semimetal). To this end, we investigate the possibility of proximity-induced ferromagnetic ordering in epitaxial Dirac semimetal (Cd$_3$As$_2$)/ferromagnetic semiconductor (Ga$_{1-x}$Mn$_x$Sb) heterostructures grown by molecular beam epitaxy. We report the comprehensive characterization of these heterostructures using structural probes (atomic force microscopy, x-ray diffraction, scanning transmission electron microscopy), angle-resolved photoemission spectroscopy, electrical magneto-transport, magnetometry, and polarized neutron reflectometry. Measurements of the magnetoresistance and Hall effect in the temperature range 2 K - 20 K show signatures that could be consistent with either a proximity effect or spin-dependent scattering of charge carriers in the Cd$_3$As$_2$ channel. Polarized neutron reflectometry sets constraints on the interpretation of the magnetotransport studies by showing that (at least for temperatures above 6 K) any induced magnetization in the Cd$_3$As$_2$ itself must be relatively small ($<$ 14 emu/cm$^3$). Show Chinese abstract

Abstract: 通过掺杂磁性离子或利用磁性近邻效应在狄拉克半金属 Cd$_3$As$_2$中打破时间反演对称性，预计会导致向其他拓扑相（如外尔半金属）的转变。 为此，我们研究了通过分子束外延生长的外延狄拉克半金属（Cd$_3$As$_2$）/铁磁半导体（Ga$_{1-x}$Mn$_x$Sb）异质结构中近邻诱导的铁磁序的可能性。 我们使用结构探测工具（原子力显微镜、X射线衍射、扫描透射电子显微镜）、角分辨光电子能谱、电学磁输运、磁强计和偏振中子反射技术对这些异质结构进行了全面表征。 在2 K - 20 K温度范围内的磁电阻和霍尔效应测量显示，这些特征可能与邻近效应或Cd$_3$As$_2$通道中电荷载流子的自旋依赖性散射一致。 极化中子反射率研究通过显示（至少对于高于6 K的温度）Cd$_3$As$_2$本身任何感应磁化必须相对较小（$<$ 14 emu/cm$^3$）来对磁输运研究的解释施加限制。