I understand that the D-Wave Quantum Annealer they have today is not a universal quantum computer.

Is the reason that it's not universal because of the lack of error correction and lack of all-to-all qubit connectivity?

Or is the reason it's not universal is that the Quantum Annealing model is not universal to begin with?


1 Answer 1


The reason is that quantum annealing is intended for solving quadratic unconstrained binary optimization (QUBO) problems. As there are tasks which cannot be converted to QUBO (e.g. Monte Carlo simulations), quantum annealers are not universal quantum processors.

A converse is true, any universal quantum processor can simulate quantum annealer.

  • 1
    $\begingroup$ what is it about quantum annealing that restricts it to only solving QUBO problems? (and for example not higher order ones). $\endgroup$ Mar 11, 2022 at 2:12
  • $\begingroup$ @bubakazouba There are techniques allowing to transform many-body interaction Hamiltonians to two-body ones but at the expense of adding many ancillas. $\endgroup$ Mar 11, 2022 at 16:29
  • $\begingroup$ Sorry I think my question wasn't clear. Why is Quantum Annealing only restricted to two-body interactions? Is it that the hardware only has limited connectivity. If it's the theoretical model, why can't we simply extend it to allow for many-body interactions? Can you point me to any resources that'd explain why this restriction exists jn tbe model? $\endgroup$ Mar 11, 2022 at 18:02
  • 1
    $\begingroup$ @bubakazouba: Please have a look for example here docs.dwavesys.com/docs/latest/c_gs_2.html. to get some insight into annealers HW. I think there were some ideas concerning possibilites of many-body interaction annealers but I have no knowledge of any article discussing this topic in detail. $\endgroup$ Mar 12, 2022 at 23:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.