Extended Data Fig. 4: Extraction of mean \(\bar{{\bf{p}}}\) and amplitude p_pp from coherently modulated switching probability traces.

In a pump–probe scheme as depicted in Fig. 3a, pairs of terahertz pulses with an adjustable delay time τ induced switching events. Although the field strength of the probe pulses was chosen to facilitate electron tunnelling into the LUMO and thereby trigger switching events, the field strength of the pump pulses was systematically varied. For non-zero pump electric fields the time-resolved switching probability traces p(τ) show oscillations at a frequency of 0.3 THz, one period of which is resolved for different field strengths of the pump pulse. The latter is indicated in the top right corner of each panel, expressed as the peak voltage of the corresponding transient (calibrated via Extended Data Fig. 3). For each curve, the time-averaged mean \(\bar{{p}}\) and amplitude p_pp are extracted by fitting a sine (solid lines) to the data.