Takahashi Hideyuki, Imai Yoshinori, Maeda Atsutaka
Organization for Advanced and Integrated Research, Kobe University, 1-1, Rokkodai, Nada, Kobe 657-8501, Japan.
Department of Basic Science, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
Rev Sci Instrum. 2016 Jun;87(6):063706. doi: 10.1063/1.4953337.
We present a design for a tunneling-current-assisted scanning near-field microwave microscope. For stable operation at cryogenic temperatures, making a small and rigid microwave probe is important. Our coaxial resonator probe has a length of approximately 30 mm and can fit inside the 2-in. bore of a superconducting magnet. The probe design includes an insulating joint, which separates DC and microwave signals without degrading the quality factor. By applying the SMM to the imaging of an electrically inhomogeneous superconductor, we obtain the spatial distribution of the microwave response with a spatial resolution of approximately 200 nm. Furthermore, we present an analysis of our SMM probe based on a simple lumped-element circuit model along with the near-field microwave measurements of silicon wafers having different conductivities.
我们展示了一种隧穿电流辅助扫描近场微波显微镜的设计。为了在低温下稳定运行，制造一个小巧且坚固的微波探头很重要。我们的同轴谐振器探头长度约为30毫米，能够适配于超导磁体的2英寸孔径内。探头设计包括一个绝缘接头，它能分离直流和微波信号而不降低品质因数。通过将该扫描近场微波显微镜应用于电不均匀超导体的成像，我们获得了空间分辨率约为200纳米的微波响应空间分布。此外，我们基于一个简单的集总元件电路模型对我们的扫描近场微波显微镜探头进行了分析，并对具有不同电导率的硅片进行了近场微波测量。
