标题： 用于高灵敏度磁力显微镜的高级杠杆式SQUID扫描探针，具有亚100纳米的空间分辨率 显示英文标题

标题： Advanced SQUID-on-lever scanning probe for high-sensitivity magnetic microscopy with sub-100-nm spatial resolution

摘要： 超导量子干涉装置（SQUIDs）是极其灵敏的磁强计，能够检测微弱的磁场。 将这些器件微型化并集成到扫描探针上，可以在低温下实现高分辨率成像。 在这里，我们通过结合晶圆级光刻和聚焦离子束（FIB）铣削，在单个平面硅悬臂的顶端制造出纳米尺度的铌SQUID，其内环尺寸缩小至10 nm。 这些坚固的SQUID探针克服了现有器件的许多限制，在4.2 K时可达到优于100 nm的空间分辨率、磁通量灵敏度为$0.3~\mu\Phi_0/\sqrt{\rm{Hz}}$，并在约0.5 T的磁场中运行。通过Ne或He-FIB进行纳米图案化，可以引入调制线以将磁通量耦合到SQUID，或引入第三个约瑟夫森结以改变其相位。 这种先进功能结合高空间分辨率、大磁场范围以及基于悬臂的扫描探针的易用性，将扫描SQUID显微镜的应用扩展到广泛的磁性、正常导电、超导和量子霍尔系统。 我们展示了在块状Cu$_2$OSeO$_3$表面的自旋涡旋磁成像。 通过对单个自旋涡旋成像得到的点扩散函数分析，得出半高全宽为87 nm。 此外，我们还对周期为65 nm的调制磁化图案进行了成像。 显示英文摘要

摘要： Superconducting quantum interference devices (SQUIDs) are exceptionally sensitive magnetometers capable of detecting weak magnetic fields. Miniaturizing these devices and integrating them onto scanning probes enables high-resolution imaging at low-temperature. Here, we fabricate nanometer-scale niobium SQUIDs with inner-loop sizes down to 10 nm at the apex of individual planar silicon cantilevers via a combination of wafer-scale optical lithography and focused-ion-beam (FIB) milling. These robust SQUID-on-lever probes overcome many of the limitations of existing devices, achieving spatial resolution better than 100 nm, magnetic flux sensitivity of $0.3~\mu\Phi_0/\sqrt{\rm{Hz}}$, and operation in magnetic fields up to about 0.5 T at 4.2 K. Nanopatterning via Ne- or He-FIB allows for the incorporation of a modulation line for coupling magnetic flux into the SQUID or a third Josephson junction for shifting its phase. Such advanced functionality, combined with high spatial resolution, large magnetic field range, and the ease of use of a cantilever-based scanning probe, extends the applicability of scanning SQUID microscopy to a wide range of magnetic, normal conducting, superconducting, and quantum Hall systems. We demonstrate magnetic imaging of skyrmions at the surface of bulk Cu$_2$OSeO$_3$. Analysis of the point spread function determined from imaging a single skyrmion yields a full-width-half-maximum of 87 nm. Moreover, we image modulated magnetization patterns with a period of 65 nm.