Causal flow preserving optimisation of quantum circuits in the ZX-calculus

Understand

Optimising quantum circuits to minimise resource usage is crucial, especially with near-term hardware limited by quantum volume.

• This paper introduces an optimisation algorithm aiming to minimise non-Clifford gate count and two-qubit gate count by building on ZX-calculus-based strategies.
• By translating a circuit into a ZX-diagram it can be simplified before being extracted back into a circuit.
• We assert that simplifications preserve a graph-theoretic property called causal flow.