Articles in 2014

The on-line isotope separation technique for the production of accelerated beams of radioactive ions has led to important advances in our understanding of atomic nuclei. These are now reviewed, and further prospects are discussed.

Monolayer films of iron selenide deposited on strontium titanate display signatures of superconductivity at temperatures as high as 109 K. These recent developments may herald a flurry of exciting findings concerning superconductivity at interfaces.

Landau levels in graphene are not equidistant so that transitions between them can be individually probed. Time-resolved optical pumping experiments reveal strong electron–electron scattering resulting in an Auger-depleted zeroth order Landau level.

Dark matter remains experimentally elusive. But what if it is more classical than expected, resembling a spatially varying field? A network of atomic clocks would be able to detect its variations.

Many quantum protocols require fast, remote entanglement generation to outperform their classical counterparts. A modular solution is now reported, using trapped ions that are remotely entangled through photons.

A proposal for detecting dark matter originating from light fields rather than particles makes use of existing networks of atomic clocks to measure time discrepancies between clocks that are spatially separated.

An imaging study of vortex proliferation near a continuous phase transition in a ferroelectric reveals frozen-in vortices that follow the predictions of the Kibble–Zurek model for cosmological strings formed in the early Universe.

Non-reciprocal components are useful in microwave engineering and photonics, but they are not without their drawbacks. A compact design now provides non-reciprocity without resorting to magnets or nonlinearity.

Falling droplets bounce back well from superhydrophobic surfaces. Now it is shown that when a thin air film is made to persist between drop and surface, efficient bouncing is possible for wettable surfaces too, and for drops with low surface tension.

Communication systems require non-reciprocal electromagnetic propagation, which is difficult to realize in circuits. An alternative is demonstrated by modulating the phase of strongly coupled resonators in a circular configuration.

Superconducting vortex droplets in a mesoscopic superconductor disintegrate in the same way as the charged liquid droplets studied by Lord Rayleigh, revealing dynamics similar to thunder clouds, atomic nuclei and trapped ultracold atoms.

Experimentalists have observed the predicted half-integer quantum Hall effect using the topological insulator BiSbTeSe₂, which exhibits topological surface states at room temperature, with each surface contributing a half quantum of Hall conductance.

Stretching a sheet of graphene could induce a superconducting state. Similar strain-induced superconductivity may be realized at the interface between a topological crystalline insulator and a trivial band insulator.

Solitons in attractive Bose–Einstein condensates are mesoscopic quantum objects that may prove useful as tools for precision measurement. A new experiment shows that collisions of matter-wave bright solitons depend crucially on their relative phase.

In topological crystalline insulators, crystal symmetries give rise to particular electronic structures. As now shown, strain further induces pseudo-Landau states in IV–VI heterostructures—a mechanism possibly responsible for the superconductivity observed in such systems.

Atomic matter waves provide a controllable platform for studying the behaviour of solitons. In a lithium condensate, a characterization of the dynamics of collisions between solitons reveals a dependence on their relative phases.

Supersymmetry and Majorana fermions that are their own antiparticles are both concepts from particle physics that may become testable in condensed-matter systems. The observation of Cooper pairs in a helical Dirac gas brings this goal a step closer.