Attosecond Photoscopy of Plasmonic Excitations

Abstract

We propose an experimental arrangement to image, with attosecond resolution, transient surface plasmonic excitations. The required modifications to state-of-the-art setups used for attosecond streaking experiments from solid surfaces only involve available technology. Buildup and lifetimes of surface plasmon polaritons can be extracted and local modulations of the exciting optical pulse can be diagnosed in situ.

Attosecond time-resolved streaked photoelectron spectroscopy of transition-metal nanospheres

“…The execution and theoretical analysis of timeresolved photoemission from nanotips [22,32], solid surfaces, and nanoparticles in sub-optical-cycle time-resolved streaking [6,31,[33][34][35][36] and RABBITT (reconstruction of attosecond beating by interference of two-photon transitions) [37][38][39][40][41] experiments add challenges in preparing and characterizing clean and atomically flat solid surfaces and size-and shapeselected nanoparticles. Compared with photoemission from isolated gaseous atoms, numerical simulations of such experiments on complex targets require, in addition, the adequate modeling of (i) the complex electronic band structure [40,42], (ii) elastic and inelastic scattering of released photoelectrons inside the solid [34,42], the excitation of surface and bulk collective electronic excitations [43][44][45], (iii) the dielectric screening and reflection [41,46] of the assisting IR-laser field at the solid surface, (iv) the influence of equilibrating residual charge distributions on emitted photoelectrons [44] and (iv) the effect of spatially inhomogeneous plasmonic fields on the photoemission process [4][5][6][19][20][21]31]. The combination of modern nanoscience and ultrafast-laser technology holds promise for enabling improved and new methods for the imaging of the spatio-temporal dielectric response of nanostructures and new ultrafast electro-optical devices [7,18,30,31,47].…”

Comparative time-resolved photoemission from the Cu(100) and Cu(111) surfaces

“…This is attributable to both, experimental challenges in preparing clean and atomically flat solid surfaces and the more complicated nature of photoemission from complex targets. In comparison to isolated gaseous atoms, photoemission from solids involves a complex electronic band structure [15,23], elastic and inelastic scattering of released photoelectrons inside the solid, including the excitation of surface and bulk plasmons [24][25][26], as well as dielectric screening [27] and reflection [13] of the assisting IR-laser field at the solid surface. While streaked photoemission from surfaces has been investigated for almost a decade, RABBITT spectra have only been recorded and analyzed very recently from solid surfaces [12,15], a notable precursor being SB studies [28,29], where the photoelectron spectra generated by a long XUV pulse and a time-delayed IR pulse were recorded.…”

Optimization of a nanotip on a surface for the ultrafast probing of propagating surface plasmons

“…In the geometry shown in Fig. 1, unlike other schemes of attosecond nanoplasmonic streaking [12,[30][31][32], the electrons' energy shift is not influenced by the incident near-infrared (NIR) laser field. None of the proposed schemes for probing SPPs using attosecond streaking proposed so far can fully separate the incident laser field from the SPP, because the incident excitation pulse occupies the same spatial region as the initial SPP, and because the SPP has only a weak field enhancement relative to the incident field, typically in the range of 0.5-1.5.…”

“…A number of femtosecond techniques, based on autocorrelation [22,23], frequency-resolved optical gating [24,25], and spectral interferometry [26], have been developed in this direction. Attosecond streaking is expected to reveal the temporal structure of plasmons with attosecond resolution [12,[27][28][29][30][31][32] and, when combined with photoelectronemission microscopy (PEEM), nanometer spatial resolution [33][34][35]. Time resolved PEEM of SPP dynamics has recently been demonstrated in the femtosecond domain [36].…”