Fig. 2: VacSe defect states accessed via ultrafast LW-STS and LW-STM.
From: Ultrafast Coulomb blockade in an atomic-scale quantum dot
a dI/dV spectra of VacSe in 1 ML (yellow) and 2 ML (turquoise) referenced to pristine WSe2 (gray). b STM topography and constant-height dI/dV orbital mapping of a top VacSe in 2 ML WSe2. The height set point z0 corresponds to Vdc = 1.2 V and Idc = 100 pA (Methods). c LW-STS of VacSe in 1 ML (yellow) and 2 ML (blue), each referenced to pristine WSe2 (gray). The tip–sample distance is z0 − 4 Å for 1 ML and z0 − 3 Å for 2 ML. d LW-STM orbital images of VacSe in 1 ML (upper panels) and 2 ML (lower panels) at THz peak voltage indicated with (i)–(iv) in (c). All lightwave measurements are performed at Vdc = 0 V. Integration time per data point is 2 s for LW-STS and 20 ms for LW-STM, corresponding to 20 M and 0.2 M THz pulses at 10 MHz repetition rate.
