A team of researchers at JILA, led by Professors Margaret Murnane and Henry Kapteyn, has developed a groundbreaking deep-ultraviolet (DUV) laser microscope that reveals how charge and heat move in materials like diamond on an incredibly small scale.
This innovation could revolutionize the development of next-generation electronics and communication systems.
Diamond is a unique material with exceptional electronic and thermal properties, making it ideal for advanced technologies.
Unlike traditional materials like silicon, diamond can handle higher voltages, operate at faster speeds, and be more efficient. However, studying its nanoscale properties has been a challenge.
Visible light, commonly used in traditional microscopes, is ineffective for probing diamonds. Diamonds don’t absorb visible light due to their wide bandgap, and visible wavelengths are too long to examine nanoscale details.
To overcome this, the JILA team designed a new microscope that uses high-energy DUV light, which interacts effectively with diamond’s structure.
The DUV microscope generates an intense laser beam with a wavelength as short as 200 nanometers—well into the ultraviolet range.
This is achieved by starting with a laser emitting longer wavelengths and passing it through nonlinear crystals to create shorter wavelengths in a step-by-step process.
Using this powerful DUV light, the team creates tiny heat patterns on a material’s surface, known as a “transient grating.”
These patterns are sinusoidal, alternating between high and low energy, and allow researchers to study how heat, electrons, and mechanical waves spread across the material.
By adjusting the laser angles, the grating size can be fine-tuned, enabling detailed analysis at a resolution of just 287 nanometers—a record for tabletop laser systems.
The team validated their system by first studying thin gold films, a material with well-understood properties.
By analyzing nanoscale heat patterns and acoustic waves on the film’s surface, they accurately measured its density and elasticity. Their experimental results matched computer models, confirming the system’s precision.
With the DUV microscope proven effective, the researchers turned their attention to diamond. Previous techniques for studying diamond required adding nanostructures or coatings, which could alter its properties. The new system eliminates this issue, allowing the team to study diamond in its pure form.
Using their setup, the team observed how charge carriers—electrons and holes—moved through diamond at the nanoscale after being excited by the DUV light. These observations provided new insights into how heat and energy behave at such small scales.
At the nanoscale, heat doesn’t always flow smoothly; instead, it can move in unexpected ways, such as traveling in straight lines (ballistic transport) or spreading like water in a channel (hydrodynamic transport).
This breakthrough could transform the development of high-performance electronics, efficient communication systems, and even quantum technologies. By enabling precise analysis of materials like diamond, the DUV microscope opens new possibilities for creating advanced devices.
While diamonds may not last forever, their potential to shape the future of technology is now clearer than ever.
