Controlled near-field enhanced electron acceleration from dielectric nanospheres with intense few-cycle laser fields

Abstract

Collective electron motion in condensed matter typically unfolds on a sub-femtosecond timescale. The well-defined electric field evolution of intense, phase-stable few-cycle laser pulses provides an ideal tool for controlling this motion. The resulting manipulation of local electric fields at nanometre spatial and attosecond temporal scales offers unique spatio-temporal control of ultrafast nonlinear processes at the nanoscale, with important implications for the advancement of nanoelectronics. Here we demonstrate the attosecond control of the collective electron motion and directional emission from isolated dielectric (SiO <inf>2</inf> ) nanoparticles with phase-stabilized few-cycle laser fields. A novel acceleration mechanism leading to the ejection of highly energetic electrons is identified by the comparison of the results to quasi-classical model calculations. The observed lightwave control in nanosized dielectrics has important implications for other material groups, including semiconductors and metals. © 2011 Macmillan Publishers Limited. All rights reserved.