Volume 10 Issue 10, October 2014

University culture stands at a critical crossroads: the era of team science is upon us functionally, but not yet structurally. Solutions to the problems this mismatch creates involve rethinking education — and giving credit where credit is due.

A superconducting surface under a drop of ionic liquid, when divided into two banks by a strip of insulating material having a single quantum point contact, becomes a device for discovering quantum phenomena.

Hybrid systems offer attractive possibilities for quantum information processing. Experiments show how off-resonant coupling to a microwave resonator can prolong the storage of photons inside a large collection of precessing spins.

Accessing orbital exchange between highly symmetric many-component spins may hold the key to a number of exotic, strongly correlated quantum phenomena, but probing such exchange is far from easy. An experiment with ultracold gases takes on the task.

The electronic coupling between two stacked atomic layers is usually weak if their periodicities are incommensurate. Optical absorption experiments have now revealed unexpectedly strong interlayer coupling in incommensurate double-walled carbon nanotubes.

The myriad creatures that inhabit the waters of our planet all swim using different mechanisms. Now, a simple relation links key physical observables of underwater locomotion, on scales ranging from millimetres to tens of metres.

Many networks interact with one another by forming multilayer networks, but these structures can lead to large cascading failures. The secret that guarantees the robustness of multilayer networks seems to be in their correlations.

Repeatedly probing a quantum system restricts its evolution, providing a route for state engineering. Such confinement, described by quantum Zeno dynamics, has now been implemented to generate superposition states in a multi-level Rydberg atom.

Hybridized systems offer a promising route for developing quantum devices, but inhomogeneous broadening limits the practical use of large spin ensembles. Suppression of the decoherence induced by such broadening has now been demonstrated for a superconducting cavity coupled to an ensemble of nitrogen–vacancy centres in diamond.

The interaction of a quantum system with its surroundings is usually detrimental, introducing decoherence. Experiments now show how such interactions can be harnessed to provide all-optical control of the spin state of a quantum dot.

Quantized resistivity values for 2D electron systems don’t necessarily result from an external magnetic field as in the ‘normal’ quantum Hall effect; they can arise due to a material's intrinsic ferromagnetism too—the quantum anomalous Hall effect. Experiments with a ferromagnetic topological insulator now establish how the anomalous states can be mapped onto the normal states.

Two concentric carbon nanotubes don’t need to have a common finite unit cell. Absorption spectra of such incommensurate double-walled carbon nanotubes reveal strong hybridization of the electron wavefunctions — unusual for van der Waals-coupled structures. The observations can be rationalized by zone folding the electronic structure of twisted-and-stretched graphene bilayers.

Electrons in graphene have a pseudospin, but controlling this degree of freedom is challenging. Evidence now suggests that the moiré superlattices arising in two-dimensional heterostructures can be used to electrically manipulate pseudospins.

Strontium titanate is a common substrate for growing oxide heterostructures—from superconductors to interfaces that support several phases of matter. But in an all-strontium-titanate device with a liquid electrolyte and metal-oxide gate, the results are anything but common.

Electron energy-loss spectroscopy uses inelastically scattered electrons to provide information about a material’s chemical composition. It is now shown that localized plasmonic excitations can lead to nonlinear scattering, significantly enhancing the signals arising from inelastic electrons.

Nonlinear inertial flows usually influence the motion of swimming organisms, but most studies focus on the tractable case of swimmers too small to feel such effects. A mechanistic principle now unifies the varied dynamics of macroscopic swimmers.

Connecting complex networks is known to exacerbate perturbations and lead to cascading failures, but natural networks of networks are surprisingly stable. A theory now proposes that network structure holds the key to understanding this paradox.

A class of van der Waals universality is introduced in the collision dynamics of three identical ultracold atoms at all scattering lengths. It is insensitive to short-range chemical details and can be computed using two-body parameters only.

In a topological material, Weyl fermions—with relativistic and Newtonian characteristics—at a quantum critical point couple to the Coulomb interaction, leading to an anisotropic screening such that the fermions are effectively non-interacting.

Using the two stable electronic states of alkaline-earth atoms, an orbital spin-exchange interaction—the building block of orbital quantum magnetism—has been observed in a fermionic quantum gas.

A date with the past.