Synthetic Spatiotemporal Plasmonic Vortices On Chip

TL;DR

This paper introduces a new class of spatiotemporal plasmonic vortices (STPVs) that intertwine orbital angular momentum in space and time, with direct imaging and control demonstrated at nanometer and attosecond scales.

Contribution

The work presents the first experimental realization and imaging of STPVs, revealing their topological spin textures and dynamics, and establishes their potential for quantum matter studies.

Findings

Direct imaging of nano-atto evolution of STPVs

Control over vortex number and position

Revelation of nonlinear plasmonic polarization fields

Abstract

Spatiotemporal vortices are polychromatic modes that intertwine orbital angular momentum (OAM) in space and time. Here we introduce a new class of such vortices, spatiotemporal plasmonic vortices (STPVs), carrying nontrivial topological spin textures. They are generated by chronotopic interference of temporally delayed plasmonic eigen-vortices, where a $\pi$-phase dislocation in the space-frequency domain maps into a 2$\pi$ spiraling phase in space-time, with the resulting focus-defocus dynamics emulate U(1) gauge transitions. Using interferometric time-resolved photoemission electron microscopy (ITR-PEEM), we directly image their nanometer-attosecond (nano-atto) evolution and control vortex number and position. Quantum-path analysis of coherent two-photon photoemission (2PP) processes reveals the nonlinear plasmonic polarization fields and angular-momentum conservation, establishing STPVs as a platform for probing spatiotemporally structured quantum matter.