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

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Scanning Tunneling Microscopy (STM) is crucial for nanoscale characterization.
• High magnetic fields and low temperatures present challenges for STM stability and performance.
• Developing instruments compatible with these extreme conditions is essential for exploring quantum phenomena.

Purpose of the Study:

• To design and evaluate a novel STM system compatible with cryogen-free superconducting magnets.
• To ensure stable atomic-resolution imaging and spectroscopy under high magnetic fields (up to 9 T) and low temperatures (down to 3 K).
• To investigate the magnetic field and temperature dependence of electronic properties in quantum materials.

Main Methods:

• The STM incorporates an isolated scanning unit with a clamped piezoelectric tube scanner (PTS) and zirconia components to minimize magnetic interference and vibrations.
• A GeckoDrive motor provides coarse approach, and the tip-sample loop is mechanically decoupled after tunneling detection.
• Shielding and grounding mitigate high-voltage signal interference, ensuring stable operation.

Main Results:

• Atomic-resolution images of graphite were obtained, demonstrating the system's performance.
• The STM exhibited excellent stability with low drift rates at room and cryogenic temperatures.
• Atomic resolution of HOPG was achieved at magnetic fields up to 9 T (300 K), and dI/dV spectra of NbSe₂ were acquired at 3 K.

Conclusions:

• The developed compact STM is highly suitable for imaging and spectroscopy in high magnetic fields and low temperatures.
• The system's stability and performance enable exploration of magnetic field effects and low-temperature electronic properties.
• This instrument facilitates advanced research in quantum and strongly correlated materials.