<story><title>D-Wave Launches Free Quantum Cloud Service</title><url>https://spectrum.ieee.org/tech-talk/computing/hardware/dwave-launches-free-quantum-cloud-service?href=</url></story><parent_chain><item><author>doitLP</author><text>Last I knew (a few months ago) we were somewhere less than 20 qubits and getting a straight answer on “does it work” depended on who was being interviewed. How do they have a 2048 qubit chip? And why is it a binary multiple? Did I miss some announcement?</text></item></parent_chain><comment><author>chriswarbo</author><text>D-wave have spent a lot of effort to show that their machine is quantum, and it seems convincing enough.&lt;p&gt;However, it&amp;#x27;s not a computer (i.e. a general-purpose machine, able to run arbitrary programs &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Universal_Turing_machine&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Universal_Turing_machine&lt;/a&gt;). Instead, their machine is a special-purpose calculator, which finds an approximate minimum value for a certain sort of problem ( &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Mathematical_optimization&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Mathematical_optimization&lt;/a&gt; ).&lt;p&gt;I always take D-wave&amp;#x27;s claims with a pinch of salt, since their original announcements were incredibly misleading. They claimed their calculator could solve problems orders of magnitude faster than a program running on a classical computer, but they turned out the be comparing apples with oranges: their machine finds an &lt;i&gt;approximate&lt;/i&gt; solution, while the program they compared against was guaranteed to find an &lt;i&gt;exact&lt;/i&gt; solution (i.e. it would carry on going until all other possibilities had been eliminated).&lt;p&gt;Other researchers did a more apples to apples comparison, by writing an approximate program (essentially simulating what the D-wave machine does). They found that a normal consumer laptop was actually much faster than the $10,000,000 D-wave machine.&lt;p&gt;D-wave&amp;#x27;s newer machines are more powerful, but I don&amp;#x27;t know if their machines benefit from the scaling properties of quantum computers (their qubits are noisy, which AFAIK prevents them all entangling completely)</text></comment>
<story><title>D-Wave Launches Free Quantum Cloud Service</title><url>https://spectrum.ieee.org/tech-talk/computing/hardware/dwave-launches-free-quantum-cloud-service?href=</url></story><parent_chain><item><author>doitLP</author><text>Last I knew (a few months ago) we were somewhere less than 20 qubits and getting a straight answer on “does it work” depended on who was being interviewed. How do they have a 2048 qubit chip? And why is it a binary multiple? Did I miss some announcement?</text></item></parent_chain><comment><author>hannob</author><text>What D-Wave is building is not what most other people mean when they say Quantum Computer.&lt;p&gt;What they build is as far as my lay understanding is something that is much more limited than a &amp;quot;normal&amp;quot; quantum computer. That&amp;#x27;s why you can&amp;#x27;t compare qubits from D-Wave with other QC technology.&lt;p&gt;What D-Wave has is technically called an adiabatic quantum computer and they&amp;#x27;ve yet to show that you can do anything useful with it.</text></comment>