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| Terahertz microscope with cryogenic insert. Credit: Department of Energy Ames National Laboratory |
A team of Ames National Laboratory scientists devised a method for collecting terahertz imaging data on materials under severe magnetic and cryogenic conditions. They used a new scanning probe microscope to complete their task.
Ames Lab just developed this microscope. The scientists measured superconductors and topological semimetals using an ultralow temperature terahertz microscope. High magnetic fields and temperatures below liquid helium (4.2 Kelvins or -452 degrees Fahrenheit) were applied to these materials.
According to Jigang Wang, a scientist at Ames Lab and professor of Physics and Astronomy at Iowa State University, the team has been working to improve their terahertz microscope since it was finished in 2019. “We have improved the resolution in terms of space, time, and energy,” Wang explained. “We have also improved operation to very low temperatures and high magnetic fields at the same time.”
Wang revealed that his team created a specialized microscopy insert for a cryostat to increase their terahertz microscope’s capability to operate in harsh cryogenic and magnetic settings. A cryostat is a device that keeps extremely frigid temperatures stable. This insert was specifically created for use with the cryogenic terahertz microscope.
The team was able to analyze superconductors and topological semimetals, both of which operate at extremely low temperatures, thanks to the novel microscope capabilities. These materials can also transfer electricity with nearly minimal energy loss, which is critical for the advancement of quantum computing technologies.
Wang believes that based on their current study, the microscope could lead to the creation of new, improved materials for highly coherent quantum devices as well as a deeper understanding of superconducting and topological materials.
This study is explored further in the publication “A sub-2 Kelvin Cryogenic Magneto-Terahertz Scattering-type Scanning Near-Field Optical Microscope (cm-THz-sSNOM),” which was published in Review of Scientific Instruments.