phase-visibility-minimum-three-row-scan - Quantum Measurement and Coherence Windows Step by Step

Phase visibility turns an ideal count into a smaller visible count by applying the coherent share. This scan keeps the ideal count fixed while the coherent share changes, so the rows bracket the minimum: above the floor, exactly equal to the floor, and below the floor. Real visibility decisions depend on preparation stability, phase noise, background subtraction, fit method, finite counts, and uncertainty.

The coherent fraction can pass, meet, or fail a visible-count floor. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Visibility is an ideal count scaled by coherent fraction

The ideal count is fixed while the coherent share changes across the rows.

N_{\text{visible}}=N_{\text{ideal}}f_{\text{coh}}

Three coherent shares bracket the minimum visible signal

The boundary row is accepted by equality; the final row is below the minimum.

\begin{array}{c|c|c|c}N_{\text{coh}}&f_{\text{coh}}&N_{\text{vis}}&m\\80&1&40&15\\50&\frac{5}{8}&25&0\\20&\frac{1}{4}&10&-15\\\end{array}

The low-coherence row fails the visible-count minimum

The phase-visibility helper computes the smaller count; the lesson gate only compares it with the minimum.

m=-15\quad \text{fail}