Quenching of material dependence in few-cycle driven electron acceleration from nanoparticles under many-particle charge interaction

All-optical spatio-temporal control of electron emission from SiO2 nanospheres with femtosecond two-color laser fields

“…The experimental setup for velocity-map imaging (VMI) of the electron emission is shown in figure 2(a). A beam of isolated SiO 2 nanoparticles was prepared via an aerosol technique [30], where the particles were brought into a gas stream of N 2 from suspension in ethanol, dried out by a diffusion dryer and focused into the laser focus with an aerodynamic lens, after which most of the residual gas was removed through differential pumping [17,[20][21][22][23]. Silica nanoparticles with diameters of 60 and 300 nm and a narrow size distribution were prepared by wet chemistry approaches.…”

“…In case of nanostructured materials, the spatial variation of the strongly localized optical near-field provides an additional control parameter for both electron emission and acceleration [17][18][19][20]. The coherent control of electron emission and acceleration with carrier-envelope phase (CEP)-controlled few-cycle laser pulses has been investigated for isolated nanospheres [19,[21][22][23], metal nanotips [24,25], and surface assembled nanostructures [26][27][28]. Characteristic nanoscale phenomena that contribute to the strong-field photoemission from these materials include (i) the transition from ponderomotive to sub-cycle electron acceleration for field localization below the scale of the electron quiver motion [29], and (ii) field propagation induced directionality of the energetic electron emission as demonstrated for nanospheres with diameters approaching the wavelength of the incident light [19].…”

Few-cycle laser driven reaction nanoscopy on aerosolized silica nanoparticles

“…Süßmann et al 14 have revealed that electrons are generated on the nanoparticle surface in the regions of maximum field enhancement and subsequently accelerated in the local near-fields. It has been shown experimentally and theoretically that released electrons gain most of their final energy from a combination of the dielectrically enhanced laser field and a local trapping potential induced by ionization 14,15,28 .…”

Strong-field physics with nanospheres

“…These effects can be accounted for in higher level descriptions such as the semi-classical Mie Mean-field Monte-Carlo (M 3 C) model [22,41,47] or via microscopic particle-in-cell (MicPic) models [62,63]. In the following, the details of M 3 C are discussed, as this method has been utilized in most of the scenarios presented in this review [41,43,44,[46][47][48]54,55,64] and was recently also extended for the description of strong-field ionization from metal nanotips [65].…”

“…For convenience, the discussion is divided into four sections. We will start the discussion in Section 4 by reviewing early surprises where rescattering from small dielectric nanospheres was first observed [36] and continue with inspecting the decisive impacts of charge interaction on the electron emission [43,44]. Section 5 focuses on the effects induced by field propagation within larger dielectric nanospheres and resulting implications and applications [41,[45][46][47][48].…”