Pi Leo ideal simulator

Introductory quantum circuit lab

Build a small circuit without writing code. Exact probabilities come from the same tested statevector engine used in the lessons.

Simulator—not physical hardware.No account key, external credential or learner information is sent to a quantum provider.

Built-in circuit lab

Build from left to right

Ideal simulator

Choose the number of qubits, add instructions with the buttons, then predict before you run. Every drag action has a keyboard button alternative.

  1. No instructions yet.
Initial state: every qubit is prepared as |0⟩.

Circuit results

Simulator
Exact probabilities and sampled results
ResultExact chanceCountSample percent
0100%

Run the simulator to create a text summary of the chart.

Bit-order legend

Pi Leo labels wires q0, q1 and q2 from top to bottom. In displayed result strings, the highest-numbered bit is written on the left, so a two-qubit result is shown as q1q0. This matches the convention used in the Pi Leo simulator and common Qiskit count strings.

Gate definitions
X
Exchanges the |0⟩ and |1⟩ reference states in these examples.
H
Changes the state direction and can create equal 0/1 measurement probabilities from |0⟩.
Z
Changes relative phase. Its effect may appear only after a later analysing gate.
CX
Applies X to a target when its control is in the |1⟩ reference state.
Measurement
Produces a classical bit result.