Inelastic Electron Tunneling as a Nanoscale Probe of Light–Matter Interactions

Project period: 2025-2030

This project aims to advance our understanding of the fundamental processes governing light–matter interactions at the extreme nanoscale and to explore strategies for manipulating them, paving the way for novel applications and advanced nanodevices.

The interaction between light and matter lies at the heart of many scientific disciplines and technologies, enabling applications in spectroscopy, sensing, lasers, and communications. Both established and emerging technologies depend critically on our ability to understand and control these interactions in nanostructures. Although light–matter interactions are intrinsically weak in free space, they can be greatly enhanced in structured media and at material interfaces, where photons couple to polarization charges in matter to form polaritons—quasiparticles with both light- and matter-like character. Recent advances in nanofabrication now allow the design of devices with atomic-scale features. However, realizing the full potential of these capabilities requires a deep understanding of the elementary processes governing light–matter interactions at the nanoscale.

In particular, the interplay between quantum tunneling and electromagnetic fields—such as light and polaritons—has emerged as a powerful approach for probing nanoscale material responses through inelastic electron tunneling. Progress in this area has nevertheless been limited by comparatively modest theoretical development, reflecting the strongly cross-disciplinary nature of the field and the limited overlap between the relevant scientific communities.

This project aims to bridge that gap by developing modern, quantum-informed theoretical frameworks toward a comprehensive understanding of light–matter physics at the extreme nanoscale. In parallel, (semi-)analytical methods and advanced computational tools will be developed to interpret experimental results and predict novel optoelectronic phenomena associated with ultraconfined polaritons at tunnel junctions composed of advanced nanostructures and emerging quantum materials. Ultimately, the project seeks to enable unprecedented control of light–matter interactions at the nanoscale, with broad implications for both fundamental science and next-generation technological applications.