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LEARNING INTERACTIVE / SINGLE-QUBIT STATE

One qubit.
Two outcomes.

Set polar angle θ and relative phase φ, then measure the same pure qubit in the Z, X, or Y basis.

State model |ψ⟩ = cos(θ/2)|0⟩ + eiφ sin(θ/2)|1⟩ θ and φ determine a general pure single-qubit state.
|0⟩
|1⟩
θ = 90° φ = 0°

01 / STATE

Angle becomes amplitude.

A pure single-qubit state is defined by polar angle θ and relative phase φ. The selected measurement basis changes which component of the Bloch vector becomes observable.

Amplitude α
0.7071
Amplitude β
0.7071
Normalization
1.0000
Bloch x
1.0000
Bloch y
0.0000
Bloch z
0.0000
Outcome |0⟩50.0%
P(0) = (1 + z) / 2
Outcome |1⟩50.0%
P(1) = (1 − z) / 2

Equal probabilities for the two computational-basis outcomes.

02 / MEASUREMENT

Probability is not a prediction.

Sample repeated measurements from the current state. Individual runs vary, while larger samples tend to approach the model probabilities.

|0⟩ count—
|1⟩ count—
Observed |0⟩—
Observed |1⟩—
Observed − expected P(0)—
Ideal sampling σ—

03 / BOUNDARIES

What this model does—and does not—show.

It does show

  • A normalized pure single-qubit state with arbitrary relative phase.
  • How θ and φ map to Bloch-vector coordinates.
  • Z, X, and Y basis probabilities from the Born rule.
  • Random sampling from those probabilities.

It does not show

  • Mixed states or density-matrix dynamics.
  • Multi-qubit entanglement.
  • Noise, decoherence, gates, or hardware calibration.
  • A connection to a quantum processor.

This is a classical browser simulation for learning and visualization. It is not a quantum-hardware emulator.