Extreme cryogenic terahertz microscope could enable breakthroughs for better quantum technology
Extreme cryogenic terahertz microscope could enable breakthroughs for better quantum technology lead image
Major scientific breakthroughs are often enabled by new technology and machines. A novel near-field optical microscope, with its high-resolution imaging at extreme temperatures and magnetic fields, may do just that for quantum computing technology and topological studies.
Kim et al. present a sub-2 Kelvin Cryogenic Magneto-Terahertz Scattering-type Scanning Near-Field Optical Microscope (cm-THz-sSNOM). THz sSNOM imaging, which uses a 300 micrometer wavelength light shining on a small metal tip to map materials on nanoscales, allows for measurements of local material properties with deep-subwavelength, 20 nanometer spatial precision — 15,000 times smaller than the wavelength of the light used. After several years of effort, the researchers were able to demonstrate an improved sSNOM platform with unparalleled resolution capabilities under extreme operating conditions.
“We have improved the resolution in terms of space, time, and energy,” said author Jigang Wang. “We have also simultaneously improved operation to very low temperatures and high magnetic fields.”
The microscope was demonstrated through measurements of superconductors and topological semimetals. The results showed the first high-resolution sSNOM images at 1.9 Kelvin in a 5 Tesla magnetic field.
The microscope could help develop new quantum bits with longer coherence time — something currently limited by material and interface defects — and improve understanding of fundamental properties of topological materials.
“It’s important to image down to billionths of a meter, quadrillionths of a second, and trillions of light waves per second to be able to select better materials and guide the fabrication of quantum and topological circuits,” Wang said.
Though the microscope has already demonstrated record-breaking measurements, the researchers aim to improve the instrument further by increasing the sensitivity and making the SUV-sized microscope more user-friendly.
Source: “A sub-2 kelvin cryogenic magneto-terahertz scattering-type scanning near-field optical microscope (cm-THz-sSNOM),” by R. H. J. Kim, J.-M. Park, S. J. Haeuser, L. Luo, and J. Wang, Review of Scientific Instruments (2023). The article can be accessed at https://doi.org/10.1063/5.0130680 .
