Quantum computers hold significant promise for peaceful applications, but one of the more immediate potential applications is breaking of public key encryption technologies. This poses significant risks to the information security of global digital infrastructure in a broader sense. At the same time, the development of quantum computing is a quintessentially scientific undertaking. There is a tension in the scientific freedom required to develop these technologies, and the measures to mitigate the risks associated with quantum computers. Policy for resolving this tension must be in line with the human right to science, read together with the right to privacy and the right to freedom of expression. In this article, I apply these rights to the development of quantum computing to provide guidance for government policy on quantum computing. I conclude that states must create the conditions for scientific research to flourish, even if this research may carry significant societal risks. This applies also to research and development of quantum technologies. In the context of quantum computing, this primarily means investing in the development and uptake of alternative encryption technologies which are resistant to attacks by quantum computers. It also means regulating the use of these technologies for applications which are undesirable.

The reliable, deterministic production of trustworthy high-quality single photons is a critical component of discrete variable, optical quantum technology. For single-photon based fully error-corrected quantum computing systems, it is estimated that photon sources will be required to produce a reliable stream of photons at rates exceeding 1 GHz (Vigliar et al., 2021). Photon multiplexing, where low probability sources are combined with switching networks to route successful production events to an output, are a potential solution but requires extremely fast single-photon switching with ultra-low-loss rates. In this paper, we examine the specific properties of the switching elements and present a new design that exploits the general one-way properties of common switching elements such as thermal pads. By introducing multiple switches to a basic, temporal multiplexing device, we can use slow switching elements in a multiplexed source being pumped at much faster rates. We model this design under multiple error channels and show that anticipated performance is now limited by the intrinsic loss rate of the optical waveguides within integrated photonic chipsets. While the developed design does not achieve the necessary 1 GHz photon rate, we demonstrate design elements that could become useful when underlying technology improves.

Artificial intelligence (AI) recently had its “iPhone moment” and adoption has drastically accelerated. Quantum computing appears poised to follow suit over the next years. However, while there has been discourse about how to use AI responsibly, there is still little appreciation and awareness among executives, managers and practitioners about the broader ethical questions and implications raised by the intersection of these emerging technologies. In this article, it is highlighted why quantum computing and AI ethics must be taken seriously by businesspersons and how these technologies affect strategic decisions; moreover, recommendations and action areas are formulated.