A selective resonance scan checks a pulse against two nearby transition gaps, 3/4 and 1/2, and only fires the transition whose gap the pulse exactly equals. The three rows use pulse 3/4 (target matched, neighbor off), pulse 1/2 (neighbor matched, target off), and pulse 1/4 (both off) exactly for the stated toy resonance rule; real selective control has finite pulse bandwidth, off-resonant driving, and crosstalk between nearby transitions.
Three pulse values probe two nearby transitions, firing only the gap they exactly match. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
A pulse tuned to the target skips the neighbor
Two nearby transitions have gaps 3/4 and 1/2. A pulse matching the target gap leaves the neighbor untouched.
pulse=43=ΔEtarget,pulse=ΔEneighbor
Three pulses probe two nearby transitions selectively
The same two gaps are tested against three pulse values. Only a pulse that exactly equals one gap fires that transition; the other gap stays off unless the pulse matches it instead.
A pulse between both gaps fires neither transition
A pulse of 1/4 matches neither exact gap, so this model marks both transitions off. Selectivity means an exact match is required, not just a nearby value.