Experimental demonstration of entanglement forging for solving Max-Cut problem

In noisy intermediate-scale quantum (NISQ) era, distributed quantum computing (DQC) has emerged as a promising direction to address limitations in qubit scalability and noise resilience. Entanglement forging is proposed as an important DQC protocol that enables the integration of the quantum computing resources and exhibits significant efficiency in realizing quantum states and dynamics with shallow entanglement. Here, we experimentally demonstrate the entanglement forging process for solving an eight-vertex Max-Cut problem. We execute parametrized quantum circuits on a four-qubit nuclear magnetic resonance quantum processor and successfully achieve the entanglement forging of the ground state for the eight-qubit Max-Cut Hamiltonian by using variational quantum eigensolver. The ground state reconstructed in experiment achieves a fidelity of 95.88% compared with theoretical prediction, which provides three correct solutions to the Max-Cut problem in parallel. Our work demonstrates the feasibility and efficiency of entanglement forging protocol in solving combinatorial optimization problems on NISQ devices, while also advancing the development of distributed quantum computing.