Boosting quantum annealer performance via sample persistence

  • Hamed KarimiEmail author
  • Gili Rosenberg


We propose a novel method for reducing the number of variables in quadratic unconstrained binary optimization problems, using a quantum annealer (or any sampler) to fix the value of a large portion of the variables to values that have a high probability of being optimal. The resulting problems are usually much easier for the quantum annealer to solve, due to their being smaller and consisting of disconnected components. This approach significantly increases the success rate and number of observations of the best known energy value in samples obtained from the quantum annealer, when compared with calling the quantum annealer without using it, even when using fewer annealing cycles. Use of the method results in a considerable improvement in success metrics even for problems with high-precision couplers and biases, which are more challenging for the quantum annealer to solve. The results are further enhanced by applying the method iteratively and combining it with classical pre-processing. We present results for both Chimera graph-structured problems and embedded problems from a real-world application.


Adiabatic quantum computation Quantum annealing Variable reduction Sample persistency Binary optimization 



The authors would like to thank Dominic Marchand, Pooya Ronagh, and Brad Woods for their insightful comments, Marko Bucyk for editing the manuscript, and Alex Selby for the use of his implementation of the Hamze–de Freitas–Selby (HFS) algorithm, available for public use on GitHub [45]. This work was supported by 1QBit and Mitacs.

Compliance with ethical standards

Conflict of interest

Hamed Karimi is an academic intern, and Gili Rosenberg is an employee at 1QBit. 1QBit is focused on solving real-world problems using quantum computers. D-Wave Systems is a minority investor in 1QBit.


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Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  1. 1.1QB Information Technologies (1QBit)VancouverCanada
  2. 2.Department of Computer ScienceUniversity of British ColumbiaVancouverCanada

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