PauliComposer: Compute Tensor Products of Pauli Matrices Efficiently

Understand

We introduce a simple algorithm that efficiently computes tensor products of Pauli matrices.

• This is done by tailoring the calculations to this specific case, which allows to avoid unnecessary calculations.
• The strength of this strategy is benchmarked against state-of-the-art techniques, showing a remarkable acceleration.
• As a side product, we provide an optimized method for one key calculus in quantum simulations: the Pauli basis decomposition of Hamiltonians.