Asymmetric Assignment Three-Row Scan - Quantum Hardware Readout: Signals and Calibration Step by Step

Real readout is often asymmetric between prepared states; three rows move from a symmetric baseline to a coin-flip one-state error rate. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Earlier scans always moved both rows together

Chapter six's diagonal-strength scan holds the two prepared-state correct rates equal by construction and moves them together. This chapter's baseline row starts equal too: both prepared states read correctly with probability 9/10.

A_{zz}=\frac{9}{10}=A_{oo}=\frac{1}{10}

This scan holds one row fixed and degrades only the other

The next two rows keep the prepared-zero correct rate fixed while only the prepared-one correct rate drops -- no earlier scan in this book holds one row fixed while moving the other alone. This is the same shape a decay-during-readout effect would leave: the excited state is harder to read correctly than the ground state.

\begin{array}{c|c}A_{zz}&A_{oo}\\\frac{9}{10}&\frac{1}{10}\\\frac{9}{10}&\frac{3}{10}\\\frac{9}{10}&\frac{1}{2}\\\end{array}

The strongest row reads prepared-one as a coin flip

In the last row, prepared one reads correctly only 1/2 of the time, while prepared zero is unchanged. The two prepared states no longer share one calibration number.

A_{zz}=\frac{9}{10},\quad A_{oo}=\frac{1}{2}