论文标题
原子量表上的拓扑磁电开关
Topological Magnetoelectric Switching on the Atomic Scale
论文作者
论文摘要
MNBI2TE4家族的固有磁性绝缘体有望实现轴突绝缘子，这是一种理论上预测的物质状态，能够相互转换电信号和磁信号，并且其特性让人联想到宇宙轴承暗物质。在这里，我们报告了拓扑超材料MNBI2TE3中室温轴子单旋旋转开关的第一个实验实现。超材料是在扫描隧道显微镜（STM）实验中原位创建的，该实验是通过使用STM尖端从MNBI2TE4表面去除TE原子层的。 MNBI2TE3的室温STM研究表明，交换间隙的原子量表变化和固定在地下缺陷处的纳米级旋转气泡的形成。我们发现，MNBI2TE3中的单个自旋状态可以使用STM尖端的局部电场可逆切换，其磁电响应与轴突绝缘子的理论预测响应相当。观察到的拓扑表面磁化明显高于散装néel温度。
Intrinsic magnetic topological insulators from MnBi2Te4 family promise realization of axion insulator, a theoretically predicted state of matter capable to mutually convert electric and magnetic signals, and whose properties are reminiscent of cosmological axion dark matter. Here we report the first experimental realization of room-temperature axionic single-spin switch in topological metamaterial MnBi2Te3. The metamaterial was in situ created in the scanning tunneling microscopy (STM) experiment by removing Te atomic layer from MnBi2Te4 surface using STM tip. Room temperature STM study of MnBi2Te3 revealed atomic scale variations of exchange gap and formation of nanoscale spin bubbles pinned at subsurface defects. We found that individual spin states in MnBi2Te3 can be reversibly switched using local electric field of STM tip with magnetoelectric response comparable to the theoretically predicted response of axion insulator. The observed topological surface magnetism develops significantly above bulk Néel temperature.
