Realizing the potential of nearterm quantum computers to solve industryrelevant constrainedoptimization problems is a promising path to quantum advantage. In this work, we consider the extractive summarization constrainedoptimization problem and demonstrate the largesttodate execution of a quantum optimization algorithm that natively preserves constraints on quantum hardware. We report results with the Quantum Alternating Operator Ansatz algorithm with a Hammingweightpreserving XY mixer (XYQAOA) on trappedion quantum computer. We successfully execute XYQAOA circuits that restrict the quantum evolution to the inconstraint subspace, using up to 20 qubits and a twoqubit gate depth of up to 159. We demonstrate the necessity of directly encoding the constraints into the quantum circuit by showing the tradeoff between the inconstraint probability and the quality of the solution that is implicit if unconstrained quantum optimization methods are used. We show that this tradeoff makes choosing good parameters difficult in general. We compare XYQAOA to the Layer Variational Quantum Eigensolver algorithm, which has a highly expressive constantdepth circuit, and the Quantum Approximate Optimization Algorithm. We discuss the respective tradeoffs of the algorithms and implications for their execution on nearterm quantum hardware.
 Award ID(s):
 1653007
 Publication Date:
 NSFPAR ID:
 10321352
 Journal Name:
 Quantum
 Volume:
 5
 ISSN:
 2521327X
 Sponsoring Org:
 National Science Foundation
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Abstract 
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