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arXiv · 1810.13411

A quantum alternating operator ansatz with hard and soft constraints for lattice protein folding

Mark Fingerhuth·Tomáš Babej·Christopher Ing
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Abstract

Gate-based universal quantum computers form a rapidly evolving field of quantum computing hardware technology. In previous work, we presented a quantum algorithm for lattice protein folding on a cubic lattice, tailored for quantum annealers. In this paper, we introduce a novel approach for solving the lattice protein folding problem on universal gate-based quantum computing architectures. Lattice protein models are coarse-grained representations of proteins that have been used extensively over the past thirty years to examine the principles of protein folding and design.These models can be used to explore a vast number of possible protein conformations and to infer structural properties of more complex atomistic protein structures. We formulate the problem as a quantum alternating operator ansatz, a member of the wider class of variational quantum/classical hybrid algorithms. To increase the probability of sampling the ground state, we propose splitting the optimization problem into hard and soft constraints. This enables us to use a previously under-utilised component of the variational algorithm to constrain the search to the subspace of solutions that satisfy the hard constraints.

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Mark Fingerhuth, Tomáš Babej, Christopher Ing. 2018-10-31. A quantum alternating operator ansatz with hard and soft constraints for lattice protein folding. https://arxiv.org/abs/1810.13411

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