Plasmonic Nanoantenna–Assisted Sub-MeV Proton Acceleration at Moderate Laser Intensities

by Konstantin Zsukovszkij (HUN-REN Wigner RCP)

Friday 15 May 2026, 11:00 → 12:00 Europe/Budapest

Tanácsterem (III. ép.)

Laser-driven proton acceleration typically requires ultrahigh intensities exceeding 1020 W/cm2 to generate relativistic hot electrons and strong electrostatic sheath fields. Here, we demonstrate via three-dimensional particle-in-cell simulations that metallic nanoantennas embedded in hydrogen-rich media enable sub-MeV proton acceleration at moderate intensities near 1018 W/cm2. Resonant nanoantennas focus femtosecond laser energy into nanoscale volumes through plasmon-enhanced near fields, driving localized electron heating and forming charge-separation fields around the structures. Three-dimensional crossed and paired nanoantennas with 3λ/2 arm lengths support hybridized plasmon modes that produce extended high-field regions for particle acceleration. These structures accelerate protons to ~0.6 MeV with two orders of magnitude lower intensity than conventional target‑normal sheath acceleration (TNSA) schemes. The study establishes plasmonic nanoantennas as nanoscale mediators of laser energy for compact, moderate-intensity proton acceleration, offering design pathways for laser-target engineering in high-power laser applications.