THz-Field-Driven Electron Tunneling on the Nanoscale

Improved control over the electromagnetic properties of metallic systems on the nanoscale is a key issue fir the development of next-generation nanoelectronics. Here, we demonstrate that intense terahertz (THz) electric fields can manipulate the electron delocalization in ultrathin gold (Au) films with nanostructures; the ultrafast electron delocalization takes place through electron tunneling across the narrow insulating bridge between the Au nanostructures. For further manipulating the THz-field-drive n electron tunneling, phase-controlled single-cycle THz near fields have been utilized in a tunnel junction via THz scanning tunneling microscopy (THz-STM). This new technique allows us to unprecedented control of electrons sub-picosecond electron burst can he produced in a single tunnel junction with desirable direction and numbers.