Off-resonant driven double well

The same driven double well is detuned from the lowest transition, so population transfer remains incomplete.

QPE preset #16

This page describes the phenomenon using the current QPE preset and numerical modules as its primary source.

Physical idea

The driven double well creates a spatial laboratory for Rabi physics. A two-level reference clarifies detuning and transfer frequency, while QPE still propagates the full wavefunction and can expose departures from the ideal two-level limit.

Key relation. A periodic bias couples two low-lying states. In the two-level limit the population oscillates at the generalized Rabi frequency Ω=√(Ω_R²+Δ²).

Guided protocol from the preset

Same system. The double well, first stationary state and bias amplitude are identical to the Rabi Resonance preset.

One change only. Drive frequency is moved to omega=0.50, away from the lowest level splitting (~0.306).

Press Play. P(state 2) grows, but never reaches the near-complete transfer of the resonant case. The system is driven, yet phase does not accumulate constructively cycle after cycle.

Then load Rabi Resonance. The contrast between the two curves makes the frequency selectivity of a coherent quantum transition directly visible.

What to observe and how to study it

Run the guided preset unchanged and first identify the observable that changes.
Change one parameter at a time, then Reset and repeat.
Always compare rendering with the Analysis readouts: the image is a view, not a complete measurement.

History and experimental status

Rabi dynamics grew out of resonance experiments on few-level systems. The same mathematics now governs qubits, atoms, spins and many coherent devices.

Representative physical scale

Representative platform	ultracold Rb-87 atom / trapped matter wave
Mapping basis	Rb-87 kinetic-unit mapping
1 QPE length unit	1 µm
1 QPE time unit	1.37 ms
Energy scale E₀=ħ/T₀	0.481 peV
Equivalent frequency E₀/h	0.116 kHz
Note	Representative cold-atom mapping. Trap frequencies, optical geometries and internal-state protocols set the actual laboratory scale; this mapping is intentionally order-of-magnitude.

The scale is an order-of-magnitude bridge from QPE dimensionless units to one plausible platform; it does not turn the preset into a quantitative simulation of that specific apparatus.

Essential references

I. I. Rabi — Space Quantization in a Gyrating Magnetic Field (Phys. Rev. 51, 652 (1937))

Continue studying

Open Model & Constraints to see exactly what QPE computes and what is left outside the model. For current live values use Help → Current Experiment → Current Parameters.