The nanometre limits of ballistic and diffusive hot-hole mediated nonlocal molecular manipulation

We report an experimental investigation into the surface-specific and experimental limits of the range of STM induced nonlocal molecular manipulation. We measure the spot-size of the nonlocal manipulation of bromobenzene molecules on the Si(111)-7 × 7 surface at room temperature at two voltages and for a wide range of charge-injection times (number of hot charge-carriers) from 1 s up to 500 s. The results conform to an initially ballistic, 6–10 nm, and then hot-hole diffusive, 10–30 nm, transport away from the localised injection site. This work gives further confirmation that nonlocal molecular manipulation by STM directly reveals the ultrafast transport properties of hot-charge carriers at surfaces. (paper)