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.
The arrow is the live (reduced) state of the selected qubit from the circuit below — entangle it and watch the arrow shrink toward the center.
Quantum Circuit Builder
Qubits & Input States
Local presets: |0>, |1>, |+>, |->, |+i>, |-i>. System presets override these.
Gate Palette
Click a gate, then click on the grid to place it.
For CNOT: click control, then target in the same column.