GeckoDrive-enabled STM for stable atomic resolution imaging in cryogen free superconducting magnet

We present the design and performance of a novel scanning tunnelling microscope (STM) that demonstrate compatibility with a cryogen-free superconducting magnet operation. The STM features an isolated scanning unit housing a tightly clamped piezoelectric tube scanner (PTS) and a zirconia shaft collectively forming the PTS unit supported by a zirconia frame. To minimize magnetic field interference, all components within the tip-sample mechanical loop are made of sapphire and zirconia. The PTS unit are clamped firmly to suppress vibrations induced by the magnet. For coarse approach, we employ an improved GeckoDrive motor capable of delivering an output force exceeding 2.2 N to actuate the tightly held PTS unit. After tunneling current detection, the tip-sample mechanical loop is mechanically decoupled from the piezo motor to suppress vibration transfer, while high-voltage signal interference is mitigated through proper shielding and grounding, ensuring stable imaging. The devices exceptional performance was validated through atomic-resolution imaging of graphite. The system demonstrates excellent stability, maintaining low drift rates in both the X-Y plane and Z direction at room and cryogenic temperatures, ensuring precise tip-sample alignment. Furthermore, we obtained atomic-resolution images of HOPG by varying the magnetic field from 0 T to 9 T at 300 K and acquired dI/dV spectra of an NbSe₂ sample at 3 K. These results indicated that our compact device is highly suitable for STM imaging and STS spectroscopy studies in high magnetic fields and low temperatures. Its high output force and stable performance make it well-suited for exploring magnetic field effects and low-temperature electronic properties in quantum and strongly correlated materials.