Room-temperature tunnel current amplifier and experimental setup for high resolution electronic spectroscopy in millikelvin STM experiments

为毫开尔文扫描隧道显微镜添加射频能力

Adding Radio Frequency Capabilities to a millikelvin Scanning Tunneling Microscope

本研究通过改进毫开尔文扫描隧道显微镜，实现了射频反射测量，用于表征超导体的射频损耗和电子温度，并展示了高灵敏度成像岛状特征的能力。

A modular ultra-high vacuum millikelvin scanning tunneling microscope

We describe the design, construction, and performance of an ultra-high vacuum (UHV) scanning tunneling microscope (STM) capable of imaging at dilution-refrigerator temperatures and equipped with a vector magnet. The primary objective of our design is to achieve a high level of modularity by partitioning the STM system into a set of easily separable, interchangeable components. This naturally segregates the UHV needs of STM instrumentation from the typically non-UHV construction of a dilution refrigerator, facilitating the usage of non-UHV materials while maintaining a fully bakeable UHV chambe…

Fast low-noise transimpedance amplifier for scanning tunneling microscopy and beyond

A transimpedance amplifier has been designed for scanning tunneling microscopy (STM). The amplifier features low noise (limited by the Johnson noise of the 1 GΩ feedback resistor at low input current and low frequencies), sufficient bandwidth for most STM applications (50 kHz at 35 pF input capacitance), a large dynamic range (0.1 pA--50 nA without range switching), and a low input voltage offset. The amplifier is also suited for placing its first stage into the cryostat of a low-temperature STM, minimizing the input capacitance and reducing the Johnson noise of the feedback resistor. The ampl…

配备绝热退磁制冷的超高真空毫开尔文扫描隧道显微镜

A millikelvin scanning tunneling microscope in ultra-high vacuum with adiabatic demagnetization refrigeration

本研究设计了一款基于绝热退磁制冷的超高真空毫开尔文STM，实现30 mK-1 K精准控温与长时稳定运行，结合隔振屏蔽设计与极简探头达成优异机械稳定性。

Millikelvin scanning tunneling microscope at 20/22 T with a graphite enabled stick-slip approach and an energy resolution below 8$μ$eV: Application to conductance quantization at 20 T in single atom point contacts of Al and Au

We describe a scanning tunneling microscope (STM) that operates at magnetic fields up to 22 Tesla and temperatures down to 80 mK. We discuss the design of the STM head, with an improved coarse approach, the vibration isolation system, and efforts to improve the energy resolution using compact filters for multiple lines. We measure the superconducting gap and Josephson effect in Aluminum and show that we can resolve features in the density of states as small as 8\,$μ$eV. We measure the quantization of conductance in atomic size contacts and make atomic resolution and density of states images in…

Low-dissipating push-pull SQUID amplifier for TES detector readout

We suggest SQUID amplifier configuration intended for millikelvin refrigerators where cooling power is limited and hence high power efficiency is desirable. The configuration operates the SQUIDs in class-AB rather than the traditional class-A. A proof-of principle demonstration at T = 4.2 K is presented.