Has Scotland always been the ‘sick man’ of Europe? An observational study from 1855 to 2006

Background: Scotland has been dubbed ‘the sick man of Europe’ on account of its higher mortality rates compared with other western European countries. It is not clear the length of time for which Scotland has had higher mortality rates. The root causes of the higher mortality in Scotland remain elusive. Methods: Life expectancy data from the Human Mortality Database were tabulated and graphed for a selection of wealthy, mainly European countries from around 1850 onwards. Results: Scotland had a life expectancy in the mid-range of countries included in the Human Mortality Database from the mid-19th century until around 1950. After 1950, Scottish life expectancy improved at a slower rate than in comparably wealthy nations before further faltering during the last 30 years. Scottish life expectancy now lies between that of western European and eastern European nations. The USA also displays a marked faltering in its life expectancy trend after 1981. There is an inverse association between life expectancy and the Index of Economic Freedom such that greater neoliberalism is associated with a smaller increase, or a decrease, in life expectancy. Conclusion: Life expectancy in Scotland has only been relatively low since around 1950. From 1980, life expectancy in Scotland, the USA and, to a greater extent, the former USSR displays a further relative faltering. It has been suggested that Scotland suffered disproportionately from the adoption of neoliberalism across the nations of the UK, and the evidence here both supports this suggestion and highlights other countries which may have suffered similarly

'Activity Theory' meets austerity - or does it? The challenge of relevance in a world of violent contradiction and crisis.

The paper critically examines the relevance of one contemporary version of 'Activity Theory' to our understanding and engagement with the current economic and political crises sweeping the world. We re-affirm the value and significance of Marx's work for our attempts to grasp the driving forces behind these crises and to articulate a way forward

Measurement-induced entanglement and teleportation on a noisy quantum processor

Measurement has a special role in quantum theory: by collapsing the wavefunction it can enable phenomena such as teleportation and thereby alter the "arrow of time" that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time that go beyond established paradigms for characterizing phases, either in or out of equilibrium. On present-day NISQ processors, the experimental realization of this physics is challenging due to noise, hardware limitations, and the stochastic nature of quantum measurement. Here we address each of these experimental challenges and investigate measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping, to avoid mid-circuit measurement and access different manifestations of the underlying phases -- from entanglement scaling to measurement-induced teleportation -- in a unified way. We obtain finite-size signatures of a phase transition with a decoding protocol that correlates the experimental measurement record with classical simulation data. The phases display sharply different sensitivity to noise, which we exploit to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realize measurement-induced physics at scales that are at the limits of current NISQ processors

Non-Abelian braiding of graph vertices in a superconducting processor

Indistinguishability of particles is a fundamental principle of quantum mechanics. For all elementary and quasiparticles observed to date - including fermions, bosons, and Abelian anyons - this principle guarantees that the braiding of identical particles leaves the system unchanged. However, in two spatial dimensions, an intriguing possibility exists: braiding of non-Abelian anyons causes rotations in a space of topologically degenerate wavefunctions. Hence, it can change the observables of the system without violating the principle of indistinguishability. Despite the well developed mathematical description of non-Abelian anyons and numerous theoretical proposals, the experimental observation of their exchange statistics has remained elusive for decades. Controllable many-body quantum states generated on quantum processors offer another path for exploring these fundamental phenomena. While efforts on conventional solid-state platforms typically involve Hamiltonian dynamics of quasi-particles, superconducting quantum processors allow for directly manipulating the many-body wavefunction via unitary gates. Building on predictions that stabilizer codes can host projective non-Abelian Ising anyons, we implement a generalized stabilizer code and unitary protocol to create and braid them. This allows us to experimentally verify the fusion rules of the anyons and braid them to realize their statistics. We then study the prospect of employing the anyons for quantum computation and utilize braiding to create an entangled state of anyons encoding three logical qubits. Our work provides new insights about non-Abelian braiding and - through the future inclusion of error correction to achieve topological protection - could open a path toward fault-tolerant quantum computing

Phase transition in Random Circuit Sampling

Quantum computers hold the promise of executing tasks beyond the capability of classical computers. Noise competes with coherent evolution and destroys long-range correlations, making it an outstanding challenge to fully leverage the computation power of near-term quantum processors. We report Random Circuit Sampling (RCS) experiments where we identify distinct phases driven by the interplay between quantum dynamics and noise. Using cross-entropy benchmarking, we observe phase boundaries which can define the computational complexity of noisy quantum evolution. We conclude by presenting an RCS experiment with 70 qubits at 24 cycles. We estimate the computational cost against improved classical methods and demonstrate that our experiment is beyond the capabilities of existing classical supercomputers