Physical units and state encoding¶
Analog controls and geometry use the following units. CASCAQit does not infer a different unit from the magnitude of a number.
| Quantity | Unit | Example |
|---|---|---|
| Position and distance | um |
Spacing 6.0 means 6 micrometres |
| Time | us |
Duration 0.2 means 0.2 microseconds |
| Rabi angular frequency and detuning | rad/us |
1 MHz as a cycle frequency converts to 2π rad/us |
| Phase and rotation angle | rad |
A pi rotation uses π |
| Van der Waals coefficient C6 | rad*um^6/us |
C6/r^6 is an angular frequency |
The coordinate model is two-dimensional. A line register uses (x, 0) positions within that model. For Analog occupations, 0 means ground and 1 means Rydberg. At zero phase, the driven two-level Hamiltonian uses Ω X / 2 − Δ n, with n = |1⟩⟨1| and ℏ = 1. See physical units for a pi-pulse calculation.
Read the recorded ordering¶
Use the result's bitstring_ordering metadata to map each position in a string to a logical qubit or atom. LocalBackend's scalable Analog results expose logical_order; Digital results can expose qubit_order. Read the accompanying convention instead of sorting names yourself. Custom register declaration order need not match alphabetical atom order, and a symmetric Bell distribution cannot reveal a reversed order.
A graph optimization candidate has its own recorded variable order. Preserve that mapping when decoding a solver's result. The bit-order lesson uses an asymmetric distribution to make the distinction visible.
Specify the interaction model¶
A finite VanDerWaalsInteraction contributes C6/r^6 for pairs inside its configured cutoff. A hard-blockade subspace instead excludes basis states according to blockade constraints. These are different models. Without finite interactions, the standalone Analog backend can automatically choose a subspace based on target metadata. Use explicit simulation options when the distinction matters; the global-drive lesson selects the full state space for an independent-atom baseline.
Digital gates and shared-state Hybrid execution are available locally. Dynamic atom movement, mid-circuit measurement and feedback are not part of this local workflow. See current limitations before choosing an experiment that requires them.