Articles in 2016

Michael de Podesta discusses the current definition of the kelvin — and why it is worth changing one last time.

Coherent population trapping in 'dark states', a well-known and much-used phenomenon in atomic physics, can also be observed in a superconducting qubit and a single nuclear spin in diamond.

Magnetic skyrmion lattices can be stabilized outside the narrow region where they are thermodynamically favoured by exploiting their topological protection.

High-temperature superconductivity in ultrathin films of iron selenide deposited on strontium titanate has been attributed to various exotic mechanisms. New experiments indicate that it may be conventional, with broader implications.

With a dedicated monthly column, Nature Physics draws attention to metrology. And a set of Commentaries in this issue focuses on various aspects of thermometry.

Sustaining and measuring high temperatures in fusion plasmas is a challenging task that requires different heating systems and diagnostic tools. Information on the spatial distribution of temperature is one of the key elements for improving and controlling plasma performance.

The redefinition of several physical base units planned for 2018 requires precise knowledge of the values of certain fundamental physical constants. Scientists are working hard to meet the deadlines for realizing the ultimate International System of Units.

In the quest for ever-lower temperatures, making new discoveries and overcoming technical challenges go hand in hand — and push the limits of thermometry standardization.

The past 25 years have seen tremendous progress in thermometry across the moderate temperature range of 1 K to 1,235 K. Various primary thermometers, based on a wide range of different physics, have uncovered errors in the International Temperature Scale of 1990, and set the stage for the planned redefinition of the kelvin.

Time- and angle-resolved photoelectron spectroscopy experiments are used to monitor the transition between Floquet–Bloch and Volkov states in the topological insulator Bi₂Se₃.

Exotic theories predict the violation of Lorentz symmetry, which could potentially be spotted in low-energy experiments. Using ytterbium ions could improve the current sensitivity bounds by five orders of magnitude.

Hydrodynamic coupling induces a vortex state in bacterial populations. Microfluidic experiments and modelling now demonstrate that lattices of these vortices can self-organize into patterns characterized by ferro- and antiferromagnetic order.

Crystal symmetries may protect single Dirac cones on the surface of a photonic crystal, creating a photonic analogue of a three-dimensional solid-state topological insulator.