Nuclear Weapons Law

This book explains in non-technical terms the law applying to the threat or use of nuclear weapons before and during an armed conflict. The rules and implications for nuclear command and control are explained, which will be relevant for politicians, lawyers, military commanders, policy staff, academics and post-graduate students. This book is also available as open access

Quantum error mitigation in quantum annealing

Quantum Error Mitigation (QEM) presents a promising near-term approach to reduce error when estimating expectation values in quantum computing. Here, we introduce QEM techniques tailored for quantum annealing, using Zero-Noise Extrapolation (ZNE). We implement ZNE through zero-temperature extrapolation as well as energy-time rescaling. We conduct experimental investigations into the quantum critical dynamics of a transverse-field Ising spin chain, demonstrating the successful mitigation of thermal noise through both of these techniques. Moreover, we show that energy-time rescaling effectively mitigates control errors in the coherent regime where the effect of thermal noise is minimal. Our ZNE results agree with exact calculations of the coherent evolution over a range of annealing times that exceeds the coherent annealing range by almost an order of magnitude.Comment: 10 pages, 5 figure

When is a cyberattack a use of force or an armed attack?

News reports and public discussion about cyberattacks appear daily in traditional and social media. Cyberattacks used in the commission of crimes, such as stealing customer credit card information, defacing websites, distributing child pornography via file-sharing sites, and creating and leasing out botnets, have become commonplace. Moreover, cyberattacks that once were considered extraordinary - in particular, those carried out as part of state-sponsored military or intelligence operations - will likely increase in frequency and severity