2022/09/25 by Hunpyo Lee, Lee, Hunpyo
Computer Science · Physics and Astronomy · #Computational Physics (physics.comp-ph) #Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Laser-Matter Interactions and Applications #Neural Networks and Reservoir Computing #Quantum Computing Algorithms and Architecture #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2209.12166
openalex publication_date 2022/09/25 · openalex created_date 2022/09/28 · openalex updated_date 2026/07/28
The D-wave quantum annealer requires embedding with ferromagnetic (FM) chains connected by several qubits, because it cannot capture exact long-range coupling between qubits, and retains the specific architecture that depends on the hardware type. Therefore, determination of the chain strength Jc required to sustain FM order of qubits in the chains is crucial for the accuracy of quantum annealing. In this study, we devise combinatorial optimization problems with ordered and disordered qubits for various embeddings to predict appropriate Jc values. We analyze the energy interval Δs and Δc between ground and first excited states in the combinatorial optimization problems without and with chains respectively, using the exact approach. We also measure the probability p that the exact ground energy per site Eg is observed in many simulated annealing shots. We demonstrate that the determination of Jc is increasingly sensitive with growing disorder of qubits in the combinatorial optimization problems. In addition, the values of appropriate Jc, where the values of p are at a maximum, increase with decreasing Δs. Finally, the appropriate value of Jc is shown to be observed at approximately Δc/Δs=0.25 and 2.1 Eg in the ordered and disordered qubits, respectively.