Letters in 2018

A periodic pattern of Cooper pairs is observed at the atomic scale and is shown to be correlated with the local strength of the superconductivity. This reveals a new interplay between different ordered states in the cuprates.

Suspended clusters of honeybees withstand dynamic mechanical forcing from their environment. Experiments and simulations suggest that collective stability relies on individual bees responding to local variations in strain.

Water drops placed at rest on flat, hot solids are found to rotate and spontaneously propel themselves in the direction of their rotation. The effect is due to symmetry breaking of the flow inside the drop, which couples rotation to translation.

Non-equilibrium Bose–Einstein condensation of 7 ± 2 photons is observed in a sculpted dye-filled microcavity. The small number of particles allows the authors to access and characterize the non-equilibrium dynamics of the bosonic modes.

Superradiance is reported from an ensemble of nitrogen–vacancy centres coupled to a microwave resonator in the fast cavity limit.

The entropy of a few-electron quantum system is measured for the first time by tracking the movement of charge in and out of the system. This could allow the unambiguous detection of Majorana fermions in solid state devices.

Demonstration of a passive swap gate between the states of a fibre-guided photonic qubit and a single atom.

The demonstration of substantially enhanced high-harmonic emission from a silicon metasurface suggests a route towards novel photonic devices based on a combination of ultrafast strong-field physics and nanofabrication technology.

Coherent driving of all transitions of a three-level system generates a closed-contour interaction, which is here shown to create efficient manipulation methods for electronic spins in nitrogen–vacancy centres in diamond.

Fluid transport at the nanoscale is important for understanding a range of phenomena in biological and physical systems. A theory accounting for transport through fluctuating channels is presented, providing a framework for designing active membranes.

Using terahertz pulses, the quasiparticle dynamics of the heavy-fermion compound CeCu_6−xAu are investigated in the vicinity of its quantum critical point.

Light–matter interactions in monolayer MoSe₂ can be dramatically modified by the interactions between the excitonic states, leading to a rich set of light-driven coherent phenomena.

Knotted lines representing torus knot and figure-eight knot are produced in the polarization profile of optical beams, leading to a topological characterization of the structure of the polarization field.

A magnetic field and temperature gradient produce a large electric potential in a ferromagnet, indicating the possible presence of Weyl points. The specific structure of Weyl points gives the electrons quantum-critical properties.

Surprising phenomena are known to occur when magnetic systems are confined to low-dimensional geometries. A resonant X-ray scattering study of NdNiO₃ slabs reveals a crossover between different magnetic ground states as a function of thickness.

A spectroscopic approach based on the Rabi resonance method is used to probe the quantum states of ultracold neutrons—and thus their interaction with the gravitational potential of the Earth.

Active colloidal particles are shown to be capable of aggregating into stable spinning clusters that constitute self-powered microgears. The demonstration reveals a new design principle for micromachinery using dissipative building blocks.

The organization of small clusters of connected cells confined to an egg chamber during early development can be mapped onto a tree packing problem. Entropically preferred packing configurations are shown to arise more readily in experiment.

Calculating the amount of radiation that can ultimately be extracted from free electrons near an arbitrary material structure is a challenge. Now, an upper limit to the spontaneous photon emission of electrons is demonstrated, regardless of geometry.

A neutron scattering study of the three-dimensional antiferromagnet Cu₃TeO₆ uncovers evidence for topological crossings in the magnon spectra of this system.