Nanocavities Revolutionize Light Confinement

Dr. Hanan Herzig Sheinfux of the Bar-Ilan University Department of Physics held groundbreaking research in Quantum Photonics with Prof. Frank Koppens and a group of European and Israeli researchers at ICFO – the Institute of Photonic Sciences in Barcelona. In a significant leap forward for quantum nanophotonics, the researchers introduced a new type of polaritonic cavities and redefined the limits of light confinement. This pioneering work, detailed in a study published in Nature Materials, demonstrates an unconventional method to confine photons, overcoming the traditional limitations in nanophotonics, and opening up new vistas for innovative applications in the areas of optics and electro-optics.

Dr. Herzig Sheinfux intends to use these cavities to see quantum effects that were previously thought impossible, as well as to further study the intriguing and counterintuitive physics of hyperbolic phonon polariton behavior.

Physicists have long been seeking ways to force photons into increasingly small volumes. The natural length scale of the photon is the wavelength and when a photon is forced into a cavity much smaller than the wavelength, it effectively becomes more "concentrated". This concentration enhances interactions with electrons, amplifying quantum processes within the cavity. However, despite significant success in confining light into deep subwavelength volumes, the effect of dissipation (optical absorption) remains a major obstacle. Photons in nanocavities are absorbed very quickly, much faster than the wavelength, and this dissipation limits the applicability of nanocavities to some of the most exciting quantum applications.

The research group addressed this challenge by creating nanocavities with an unparalleled combination of subwavelength volume and extended lifetime. These nanocavities, measuring less than 100x100nm² in area and only 3nm in width, confine light for significantly longer durations. The key lies in the use of hyperbolic-phonon-polaritons, unique electromagnetic excitations occurring in the 2D material forming the cavity.

“Experimental measurements are usually worse than theory would suggest, but in this case, we found the experiments outperformed the optimistic simplified theoretical predictions,” said first author, Dr. Herzig Sheinfux. “This unexpected success opens doors to novel applications and advancements in quantum photonics, pushing the boundaries of what we thought was possible.”