Although carbon nanotubes are not superconductors, they can carry supercurrents injected from superconducting contacts. Analysis of the tunnelling spectra of a nanotube connecting two superconductors reveals the detailed electronic structure ofdiscrete entangled electron–hole states that carry the resulting supercurrent. Letter p965; News & Views p940 Cover design by David Shand

The spreading of information, ideas or diseases can be conveniently modelled in the context of complex networks. An analysis now reveals that the most efficient spreaders are not always necessarily the most connected agents in a network. Instead, the position of an agent relative to the hierarchical topological organization of the network might be as important as its connectivity. Letter p888 Cover design by David Shand

Micrometre-scale superconducting circuits are being explored as the building blocks of scalable quantum information processors. In a system where two such qubits are coupled to a resonant cavity, tripartite interactions and controlled coherent dynamics have now been demonstrated. This platform should enable a fuller exploration of multipartite quantum states and their deterministic preparation. Letter p777 Cover design by David Shand

Symmetry-breaking transitions occur over femtosecond timescales in the solid state. This makes it difficult to study the dynamics that drive such a system from a high-symmetry state to a broken-symmetry state. A triple-pulse femtosecond spectroscopic technique enables the details of the evolution of a symmetry breaking charge-order transition in terbium telluride to be studied with unprecedented temporal resolution. Letter p681; News & Views p639 Cover design by David Shand

The presence of grain boundaries between misaligned crystallites is known to limit the supercurrent in a superconductor. A microscopic-based theory now reveals that charge inhomogeneities can build up at a grain boundary, blocking the superconducting current. Article p609; News & Views p559 Cover design by David Shand

A dye-filled optical microresonator can trap photons such that their number doesn't decrease even when the 'white box' is cooled. An intriguing consequence is that light becomes concentrated in the centre of the confining potential. Such photon thermalization is an important step towards a Bose—Einstein condensate of light. Letter p512 Cover design by David Shand

When a fluid flows along a wall, the surface of the wall causes frictional drag. The long-sought connection between this drag and the eddies in the flow has finally been established through experiments on a soap film that is pierced by a turbulence-inducing comb. Letter p438 Cover design by David Shand

The valence and conduction electrons of perfect crystals usually exist in continuous bands of states that extend throughout a crystal’s bulk, whereas those in the innermost shells of its constituent atoms are usually tightly confined to the orbitals of individual atoms. However, angular variations in the photoemission spectra of graphene suggest that its carbon 1s states have an extended band-like character. Letter p345 Cover design by David Shand

Superconducting quantum interference devices based on the Josephson effect have enabled significant improvements in the sensitivity of magnetic-field measurements. Similar devices that incorporate sections of non-superconducting metal into a superconducting ring exploit a phenomenon known as the proximity effect to realize further improvements in magnetic-field sensitivity. Letter p254 Cover design by David Shand

The ability of X-rays to penetrate deep into a sample is one of their many useful properties. But it also means that it's difficult to build mirrors to manipulate X-rays; most are based on total external reflection at grazing incidence. it is now shown, however, that the near-normal X-ray reflectance of regions of an off-the-shelf commercial diamond crystal can reach as high as 90% — which could lead to the development of a new class of high-performance X-ray optics. Letter p196; News & Views p163 Cover design by David Shand

Guided by a general framework for wavefront engineering, experiments demonstrate that in a light field, lines of zero intensity can be shaped into knotted and linked loops of arbitrary topology. Letter p118 Cover design by David Shand

Analysing the response of graphene to strain suggests that it should be possible to induce pseudomagnetic behaviour, and even zero-field quantum Hall effects, by simply bending it in the right way. Letter p30 Cover design by David Shand