Even 21 was only possible by cheating (optimizing away the difficult part using prior knowledge of the results) [1]. Craig Gidney has a blog post that shows the actual quantum circuit for factoring 21 which is far beyond the capabilities of current quantum computers [2].
Even 21 was only possible by cheating (optimizing away the difficult part using prior knowledge of the results) [1]. Craig Gidney has a blog post that shows the actual quantum circuit for factoring 21 which is far beyond the capabilities of current quantum computers [2].
[1] https://www.nature.com/articles/nature12290
[2] https://algassert.com/post/2500
And it was done in 2012. I admit I’m surprised there hasn’t been more progress since.