Shared Mode Addressed-Ion Cross-Scan - Ion-Trap Qubits: Sidebands, Shared Modes, and Fluorescence Readout Step by Step

This scan separates the addressed ion label from the shared motion packet ledger. Ion A and ion B can both use the red sideband to move packet 2 to 1, while ion B on the blue sideband moves packet 2 to 3. In real traps, addressing beams, cross-talk, mode heating, calibration drift, and readout uncertainty decide how well that clean shared-mode ledger survives.

Addressing either ion still updates the same shared motional packet ledger. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Ion a uses red

The addressed ion is A. The shared mode records packet 2 to 1 from the cited sideband.

n_{\text{shared}}:2\to1,\quad a=1

Ion b uses red

The addressed ion is B. The shared mode records packet 2 to 1 from the cited sideband.

n_{\text{shared}}:2\to1,\quad a=1

Ion b uses blue

The addressed ion is B. The shared mode records packet 2 to 3 from the cited sideband.

n_{\text{shared}}:2\to3,\quad a=1

The shared packet belongs to the mode, not to a private ion

Changing which ion is addressed does not create a second packet ledger. The red rows end at one; the blue row ends at three.

\begin{array}{c|c|c|c}\text{row}&n_{\text{start}}&n_{\text{end}}&a\\\text{ion A uses red}&2&1&1\\\text{ion B uses red}&2&1&1\\\text{ion B uses blue}&2&3&1\\\end{array}