Rigel — Quantum Playground
A quick tour of the Bloch sphere, then a toy quantum circuit simulator you can play with.
Drag the sphere to rotate it. Pure states live on the surface; the center is maximally mixed.
Each sphere is the live (reduced) state of one qubit from the circuit below, labelled q0, q1 and so on. Entangle two qubits and watch both arrows shrink toward the center.
Quantum Circuit Builder
Qubits & Input States
Local presets: |0⟩, |1⟩, |+⟩, |−⟩, |+i⟩, |−i⟩. System presets override these.
Gate Palette
Circuit
Pick a gate, then click a slot on a wire. Right-click or press Delete to remove a gate. Arrow keys move between slots.