Sakellariou Jason, Askitopoulos Alexis, Pastras Georgios, Tsintzos Symeon I
QUBITECH, Thessalias 8, GR 15231 Chalandri, Athens, Greece.
UBITECH Ltd., 95B Archiepiskopou Makariou, CY 3020 Limassol, Cyprus.
Phys Rev Lett. 2025 May 23;134(20):203801. doi: 10.1103/PhysRevLett.134.203801.
Photonic Ising machines constitute an emergent new paradigm of computation geared toward tackling combinatorial optimization problems that can be reduced to the problem of finding the ground state of an Ising model. Spatial photonic Ising machines (SPIMs) have proven advantageous for simulating fully connected large-scale spin systems. Fine control of a general interaction matrix J has been accomplished so far only through matrix decomposition methods. We introduce and experimentally validate a SPIM instance that enables direct control over the full interaction matrix, allowing the encoding of Ising Hamiltonians with arbitrary couplings and connectivity. We demonstrate the conformity of the experimentally measured Ising energy with the theoretically expected value and then proceed to solve both the unweighted and weighted graph partitioning problems, showcasing a systematic convergence to an optimal solution via simulated annealing. Our approach significantly expands the applicability of SPIMs for real-world applications, as it is more efficient than matrix decomposition methods in the case of sparse problems. It paves the way to encoding the full range of NP problems that are known to be equivalent to Ising models on SPIM devices.
光子伊辛机构成了一种新兴的计算范式，旨在解决可简化为寻找伊辛模型基态问题的组合优化问题。空间光子伊辛机（SPIM）已被证明在模拟全连接大规模自旋系统方面具有优势。到目前为止，对一般相互作用矩阵J的精细控制仅通过矩阵分解方法实现。我们引入并通过实验验证了一个SPIM实例，该实例能够直接控制完整的相互作用矩阵，允许对具有任意耦合和连通性的伊辛哈密顿量进行编码。我们证明了实验测量的伊辛能量与理论预期值的一致性，然后着手解决无加权和加权图划分问题，通过模拟退火展示了向最优解的系统收敛。我们的方法显著扩展了SPIM在实际应用中的适用性，因为在稀疏问题的情况下，它比矩阵分解方法更有效。它为在SPIM设备上编码已知与伊辛模型等价的全范围NP问题铺平了道路。
