Atomically resolved scanning tunneling microscope for use in a 42 T resistive magnet

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• High magnetic field Scanning Tunneling Microscopy (STM) is crucial for exploring material properties.
• Existing STM systems are limited to fields below 20 T due to stability and environmental constraints.
• Atomic resolution STM in ultra-high magnetic fields (>40 T) has not been achieved previously.

Purpose of the Study:

• To develop a novel STM system capable of atomic resolution imaging in ultra-high magnetic fields.
• To overcome the challenges of vibration and stability in extreme magnetic environments.
• To expand the capabilities of STM for investigating quantum materials.

Main Methods:

• Designed a novel STM head with a nested piezoelectric tube motor for independent tip control.
• Mechanically decoupled the scanner from the motor to reduce external vibration interference.
• Integrated a custom liquid helium cryostat and a two-stage vibration isolation system.

Main Results:

• Achieved atomic-resolution imaging of Highly Oriented Pyrolytic Graphite (HOPG) from 300 K down to 1.6 K.
• Obtained atomic-resolution images of HOPG at magnetic fields up to 42 T at 150 K.
• Demonstrated high stability and spectroscopic capability through low drift rates and dI/dV spectra.

Conclusions:

• Developed the world's first STM capable of atomic resolution at 42 T.
• The new system significantly expands the research scope for STM in ultra-high magnetic fields.
• This advancement enables new investigations into the physical properties of materials under extreme conditions.