Articles in 2016

Physicists have finally detected gravitational waves, in a triumph of ingenuity and perseverance. And now we need to explain them to the general public.

In the transition from laminar to turbulent pipe flow, puffs of turbulence form, split and decay. The phenomenology and lifetime of these turbulent puffs exhibit population dynamics that also drive predator–prey ecosystems on the edge of extinction.

Intense light pulses irradiating a sample of K₃C₆₀ result in dramatic changes of its high-frequency (terahertz) conductivity. Could these be signatures of fleeting superconductivity at 100 K and beyond?

In some two-dimensional materials, there's a puzzling intermediate metallic phase between superconducting and insulating states. Experiments on ultraclean crystalline samples suggest this metallic phase could be bosonic.

For a problem as complex as turbulence, combining universal concepts from statistical physics with ideas from fluid mechanics has proven indispensable. Three decades since this link was formed, it is still providing food for new thought.

François Piquemal tells the story of the ampere, which bridges mechanical and electromagnetic units.

Three-dimensional rogue waves have been observed in a dusty-plasma system, which provides a wave–particle interaction view on their formation.

Spin–orbit coupling in two dimensions is essential for observing topological phases in ultracold atoms. Such a coupling was produced in a gas of potassium atoms and a robust Dirac point was observed in the energy dispersions of the dressed atoms.

Coherent valley exciton dynamics are directly probed in a monolayer transition metal dichalcogenide, providing access to the valley coherence time and decoherence mechanisms — crucial for developing methods for manipulating the valley pseudospin.

The magnetic response of nanoparticles made from wide-bandgap oxides that don’t contain any magnetic cations is somewhat of a mystery. Experiments with CeO₂ suggest that the origin may be due to vacuum fluctuations.

Rogue waves have been observed in fluids and other wave contexts. Experiments now show the formation of 3D acoustic rogue waves in dusty plasmas; they result from wave–particle interactions driving the dust particles into high-amplitude dynamics.

Single carbon vacancies in graphene can host a positive charge that is tunable. When this charge is large enough such vacancies resemble artificial atoms, with an induced sequence of quasi-bound states that trap nearby electrons.

In analogy to fluids, electric currents can exhibit viscosity — albeit with effects difficult to observe experimentally. Now, vorticity is reported as a signature feature of electron viscosity in graphene, which leads to negative nonlocal resistance.

Two intriguing manifestations of Hall physics are reported in a topologically insulating heterostructure: a sign-reversal of the anomalous Hall effect and the emergence of a topological Hall effect.

In a Fermi gas with s-wave interactions the contact relations link the thermodynamic and microscopic properties. For the p-wave case two new types of contacts that characterize the interactions have now been measured experimentally.

The concept of an evolving jamming density explains a multitude of mechanisms in granular matter. Simulations of systems with friction now consolidate this notion and highlight that the jamming point is a variable that can move in various ways whenever the system is deformed.

Amorphous packings of spheres subject to shear and friction jam above a critical density. Simulations now show that shear results in geometrical patterns that are precursors to jammed structures and that friction effectuates the jamming.