Lab
Circuit Lab
The games teach one idea each. This is the open bench. Build any circuit on up to five qubits and watch the exact state answer every change — amplitudes with phases, each qubit's Bloch vector, the density matrix under noise, and real sampled measurements. Nothing here is pre-rendered: the engine runs on every click.
Intuition to form: put a gate in, watch the bars. Add a CNOT and see a qubit's Bloch arrow shrink to nothing — entanglement, measured. Turn up noise and watch purity fall; that is what error correction fights and ZNE extrapolates away. Start from the learning path if the gates are new.
Build
Pick a gate, then click a wire. Two-qubit gates: click control, then target.
Hadamard — puts a basis state into equal superposition.
Exact state
The full statevector — amplitude, phase, probability for every basis state.
Each qubit alone
Reduced Bloch vectors. Entangled qubits shrink toward the center — information has left the individual.
Noise
A depolarizing channel after every gate — exact density matrix, the same model the VQE suite's ZNE uses.
Measure
1024 real shots sampled from the ideal distribution. Randomness is the physics, not a decoration.
OpenQASM 2.0
Your circuit as code. Paste it into the transpiler to compile it to Amazon Braket IR.
OPENQASM 2.0; include "qelib1.inc"; qreg q[2]; creg c[2]; h q[0]; cx q[0],q[1]; measure q -> c;