Using the optical pump-probe technique, the dynamics of electrons in bulk and two-dimensional condensed matter systems can be studied with femtosecond (1fs=10^-15s) time resolution. The spatial resolution is however limited by diffraction and is therefore insufficient to investigate single nanostructures or molecules. This restraint can be overcome by coupling ultrashort laser pulses with plasmonic nanostructures, which concentrate the incoming electromagnetic field to subwavelength volumes. Focusing phase-stable single-cycle terahertz (THz) pulses onto the nanojunction of a scanning tunnelling microscope (STM), control of coherent photocurrents with atomic spatial and sub-picosecond temporal resolution has been demonstrated. This opened up the possibility of investigating vibrational modes of molecules or crystal lattices directly at their natural spatiotemporal scales. Nevertheless, electronic wavepackets evolve at faster timescales and typically require sub-10fs time resolution.
Here we explore the possibility of employing near-infrared (near-IR) laser pulses to further improve the time resolution of scanning tunnelling microscopy down to the femtosecond domain. As a first step in this direction, we will discuss how phase-stable single-cycle near-IR transients can be synthesized and used to optically control field-emission across a plasmonic nanogap.  We will then address the additional challenges that arise when driving field-induced tunnelling currents across the junction of an actual STM. Contrarily to the THz case, photoemission at near-IR frequencies can be dominated by photothermal and multiphoton processes, which makes the detection of coherent laser-induced tunnelling currents extremely challenging. In this context, we propose a novel approach to isolate coherent photocurrents, potentially paving the way towards ultrafast experiments with sub-10fs time resolution at the atomic scale.