Ultrafast Science Breakthroughs in Metal-Insulator-Metal Tunneling Nanojunctions

Researchers at the Technion-Israel Institute of Technology have made significant progress in the field of ultrafast science, specifically in the dynamics of electrons in matter with extreme temporal precision. By developing a robust strong-field theory model, the team has provided a comprehensive understanding of ultrafast electron transport through metal-insulator-metal (MIM) tunneling nanojunctions. This breakthrough has far-reaching implications for petahertz electronic operation and attosecondscale scanning tunneling microscopy.

Key Takeaways:

• The research team, led by the Technion-Israel Institute of Technology, has developed a robust strong-field theory model for ultrafast electron transport through MIM nanojunctions.
• The model provides a rich toolbox for understanding and predicting the physics of ultrafast MIM nanojunctions, accounting for image potential inside the gap and boundary effects.
• The team found that the Keldysh parameter, a hallmark parameter for ultrafast light-matter interactions, is insufficient for describing the physics in thin MIM nanojunctions, requiring a new parameter to account for the limited size of the junction.
• The new parameter has several interpretations that shed new light on the complex physics in the light-driven junction, revealing striking insights into ultrafast electron transport.
• The research concluded that one-photon-assisted tunneling is dominating the ultrafast electron transport across the junction, regardless of the value of the Keldysh parameter.

Statistics:

• The research team used an ultrafast laser field to induce currents in the MIM nanojunctions, operating at the petahertz frequency.
• The study was supported by Horizon 2020 and the Israel Science Foundation.
• The research was peer-reviewed and published in Physical Review A, Volume 112, Issue 3, 2025.
• The American Physical Society, publisher of Physical Review A, is headquartered in Maryland, USA.

Sources:

• Robust Strong-field Theory Model for Ultrafast Electron Transport Through Metal-insulator-metal Tunneling Nanojunctions. Physical Review A, 2025;112(3). Amer Physical Soc, One Physics Ellipse, College Pk, MD 20740-3844, USA.
• NewsRx. Findings on Nanojunctions Discussed by Investigators at Technion-Israel Institute of Technology (Robust Strong-field Theory Model for Ultrafast Electron Transport Through Metal-insulator-metal Tunneling Nanojunctions). Nanotechnology Weekly. October 20, 2025; p 460.