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Bibliographic Details
Main Authors: Shirai, Tatsuhiko, Togawa, Nozomu
Format: Preprint
Published: 2023
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Online Access:https://arxiv.org/abs/2309.08120
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author Shirai, Tatsuhiko
Togawa, Nozomu
author_facet Shirai, Tatsuhiko
Togawa, Nozomu
contents We propose a post-processing variationally scheduled quantum algorithm (pVSQA) for solving constrained combinatorial optimization problems (COPs). COPs are typically transformed into ground-state search problems of the Ising model on a quantum annealer or gate-type quantum device. Variational methods are used to find an optimal schedule function that leads to high-quality solutions in a short amount of time. Post-processing techniques convert the output solutions of the quantum devices to satisfy the constraints of the COPs. pVSQA combines the variational methods and the post-processing technique. We obtain a sufficient condition for constrained COPs to apply pVSQA based on a greedy post-processing algorithm. We apply the proposed method to two constrained NP-hard COPs: the graph partitioning problem and the quadratic knapsack problem. pVSQA on a simulator shows that a small number of variational parameters is sufficient to achieve a (near-)optimal performance within a predetermined operation time. Then building upon the simulator results, we implement pVSQA on a quantum annealer and a gate-type quantum device. The experimental results demonstrate the effectiveness of our proposed method.
format Preprint
id arxiv_https___arxiv_org_abs_2309_08120
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Post-processing variationally scheduled quantum algorithm for constrained combinatorial optimization problems
Shirai, Tatsuhiko
Togawa, Nozomu
Quantum Physics
We propose a post-processing variationally scheduled quantum algorithm (pVSQA) for solving constrained combinatorial optimization problems (COPs). COPs are typically transformed into ground-state search problems of the Ising model on a quantum annealer or gate-type quantum device. Variational methods are used to find an optimal schedule function that leads to high-quality solutions in a short amount of time. Post-processing techniques convert the output solutions of the quantum devices to satisfy the constraints of the COPs. pVSQA combines the variational methods and the post-processing technique. We obtain a sufficient condition for constrained COPs to apply pVSQA based on a greedy post-processing algorithm. We apply the proposed method to two constrained NP-hard COPs: the graph partitioning problem and the quadratic knapsack problem. pVSQA on a simulator shows that a small number of variational parameters is sufficient to achieve a (near-)optimal performance within a predetermined operation time. Then building upon the simulator results, we implement pVSQA on a quantum annealer and a gate-type quantum device. The experimental results demonstrate the effectiveness of our proposed method.
title Post-processing variationally scheduled quantum algorithm for constrained combinatorial optimization problems
topic Quantum Physics
url https://arxiv.org/abs/2309.08120