Improved Algorithms for Quantum MaxCut via Partially Entangled Matchings

Anuj Apte, Eunou Lee, Kunal Marwaha, Ojas Parekh, James Sud (Apr 22 2025).

Abstract: We introduce a $0.611$-approximation algorithm for Quantum MaxCut and a $\frac{1+\sqrt{5}}{4} \approx 0.809$-approximation algorithm for the EPR Hamiltonian of [arXiv:2209.02589]. A novel ingredient in both of these algorithms is to partially entangle pairs of qubits associated to edges in a matching, while preserving the direction of their single-qubit Bloch vectors. This allows us to interpolate between product states and matching-based states with a tunable parameter.

Arxiv: https://arxiv.org/abs/2504.15276