Nikesh S. Dattani, Nathaniel Bryans
The largest number factored on a quantum device reported until now was 143.
That quantum computation, which used only 4 qubits, actually also factored much larger numbers such as 3599, 13081, and 44929, without the awareness of the authors of that work.
Furthermore, unlike the implementations of Shor’s algorithm performed thus far, these 4-qubit factorizations do not need to use prior knowledge of the answer. However, because they only use 4 qubits, these factorizations can also be performed trivially on classical computers. We discover a class of numbers for which the power of quantum information actually comes into play.
We then demonstrate a 3-qubit factorization of 175, which would be the first quantum factorization of a triprime.
Read more at http://arxiv.org/pdf/1411.6758v2.pdf