The paper by Sanguinetti et al. (Phys. Rev. X, 4 031056 (2014)) reporting generation of quantum random numbers on a commercial mobile phone has just “come off the press.” Having it reviewed and reaching the final decision to publish it has been a challenging, but also very interesting, process for the editors. We think there is value in sharing with our readers our thinking behind the decision.
PRX is a highly selective journal that aims to publish and disseminate important physics research results to a broad readership. For us, its editors, it is therefore necessary to ask the following questions about any paper we consider: Does the paper in question discover and teach us new and significant physics? Is it of the highest scientific quality? How will the paper impact the current research or enable new research? What is its fundamental or technological potential? Will it appeal to our broad readership?
A compelling “yes” to all of these questions naturally makes the editorial decision to publish the paper in question an “easy” one. But what do we do when that’s not the case, as for the paper by Sanguinetti et al.?
Right from the very beginning of the editorial and peer-review process, we had split views, i.e., we were on the fence about the suitability of the paper. On the one hand, the key scientific concepts and tools used in this work, including quantum random number generation (QRNG), photon detection in the quantum shot-noise limit, and randomness extractors are known or already developed, and the basic physics at play is also well understood. This fact seemed detrimental for the paper’s suitability for PRX.
On the other hand, the insight that cameras on commercial mobile phones today may be capable of detecting the fundamentally random quantum noise in most light sources seemed refreshingly original. The way the researchers combined known concepts and techniques to experimentally verify this insight and to actually generate high-quality random number sequences using this capability appeared technically ingenious, and the technological potential of the work, involving a device that is literally at the fingertips of billions of people, could not be dismissed just because we can’t be certain of its impact at present. Last, but not least, we expected that the scientific message would appeal to many readers, whether they are scientists or laypeople.
Given this ambivalence, we consulted expert reviewers, and we also asked our Editorial Board to weigh in. Their input solidified, indeed accentuated, that ambivalence. After extensive deliberation involving all the editors, however, we came to the conclusion in the end that we should give the paper a place in PRX for the conceptual novelty in its insight, for its technical ingenuity and its potential technological impact, and for its broad appeal. We are pleased to publish the paper and hope that our readers will enjoy and appreciate its scientific message.