Someone offhandedly mentioned to me that quantum computers are sometimes significantly (I guess they meant asymptotically) slower than classical computers. Unfortunately, I didn't get any arguments nor examples for this statement, and I'm not able to figure the limitations out myself.

I tried to look up articles on the web and questions on StackExchange, but everything is about the problems where quantum computers are faster. None of them mention how solutions to the rest of the problems compare in speed, at least not what I could find.

Question: What are examples where quantum computers are significantly/asymptotically slower than classical computers?

  • 5
    $\begingroup$ It seems like that person is talking about the time it takes to perform quantum logical gate (gate speed)... For devices using superconducting qubit technology, I think this is in MHz. Comparing to classical, this is being done in the GHz so it is indeed slower in that sense... The advantage of quantum computing is indeed not about being faster processor, but rather in the way quantum computer allows us to design algorithm that is better, in term of complexity, than classical algorithms. $\endgroup$
    – KAJ226
    Commented May 24, 2021 at 14:51


Your Answer

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