Design and Performance of an Ultrahigh Vacuum Spectroscopic Imaging - Scanning Tunneling Microscope with a Hybrid Vibration Isolation System

Pei-Fang Chung^1*, Balaji Venkatesan^1,2,3, Chih-Chuan Su¹, Jen-Te Chang¹, Che-An Liu¹, Shan-An Yu¹, Syu-You Guan¹, Tien-Ming Chuang¹

¹Institute of Physics, Academia Sinica, Taipei, Taiwan
²Department of Physics, National Taiwan University, Taipei, Taiwan
³Nano Science and Technology Program, Taiwan International Graduate Program, Taipei, Taiwan

* Presenter:Pei-Fang Chung, email:pfchung@gate.sinica.edu.tw

A spectroscopic imaging-scanning tunneling microscope (SI-STM) allows the atomic scale visualization of surface electronic and magnetic structure of novel quantum materials with high energy resolution. Here, we describe the design and the performance an ultrahigh vacuum SI-STM system supported by a hybrid vibration isolation system that consists of a passive pneumatic passive and an active piezoelectric vibration isolation stages. The SI-STM is equipped with a 1K pot cryogenic insert and a 9 Tesla superconducting magnet, capable of continuous spectroscopy measurements for 7 days. A field ion microscopy system is installed for the in situ STM tip treatment. We present the detailed vibrational noise analysis of the hybrid vibration isolation system and demonstrate the performance of our SI-STM system by measuring atomically registered energy-resolved spectroscopic maps and topographic images on NbSe₂. Our results establish a new strategy to achieve an effective vibration isolation system for high-resolution SI-STM and other scanning probe microscopy to investigate the nanoscale quantum phenomena.

Keywords: Scanning probe microscope , spectroscopic imaging-scanning tunneling microscope, Vibration isolation system, Superconducting magnet Dewar