Bad Qubits — Learn Quantum by Doing

Multiple choice

In first-order Trotterization, e^(-i(H1+H2)t) is approximated as e^(-iH1*t) e^(-iH2*t). The operator error is proportional to the commutator [H1, H2]. What happens when H1 and H2 commute?

The approximation becomes exact (zero error), since [H1, H2] = 0
The error grows exponentially with the simulation time
The error doubles compared with the non-commuting case
The approximation is undefined and cannot be used