Spin Echo Noise Compensator

Real qubits don't stay coherent on their own — a fluctuating local field detunes each one slightly differently, and an ensemble that starts in phase fans apart within microseconds, the T2* dephasing that limits every gate-based quantum processor. This simulator renders that fanning-out directly: sixty qubits sit on the equator of a shared Bloch sphere, each precessing at its own randomly drawn detuning, and the bright ensemble-average arrow shrinks as they lose mutual phase. Switching on Hahn-echo or multi-pulse CPMG dynamical decoupling fires timed π-pulses that flip each qubit's accumulated phase sign, so the very noise that caused the dephasing undoes itself — the arrow snaps back toward full length at every refocusing time, exactly the trick real quantum hardware uses to buy extra coherent time between operations.