RXX(θ) = cos(θ/2)I − i sin(θ/2)X⊗X; C = |sin θ|; d³ = 2kₑe²/(mωz²); ωCOM = ωz; ωstretch = √3ωz
Assumptions and limits
- Only the selected pair is a simulated quantum register. It starts in |00⟩, in basis order 00, 01, 10, 11. The other four numbered ions provide architecture context.
- The gate angle is in radians, not elapsed hardware time. Transport progress changes the drawing only and does not apply a logical SWAP or alter the modeled state.
- The motion inset uses isolated equal-mass singly charged ions with illustrative mass 171u and a harmonic axial trap. Frequencies are MHz; displayed separation follows Coulomb equilibrium.
- The inset shows enlarged classical normal-mode displacements about equilibrium, not literal ground-state trajectories. Its M1/M2 markers are separate from Q1–Q6.
- Ideal unitary dynamics exclude motional heating, imperfect cooling, leakage, pulse errors, crosstalk and readout errors. Probabilities are analytical model outputs, not hardware measurements.
- Architecture positions and regrouping paths are conceptual and not to scale. Electrodes provide confinement; the drawing omits optical hardware, detailed trap voltages, ion reordering and spectator motion.
Sources · 6 references
