Letters

Using a superconducting transmon qubit coupled to a microwave photonic crystal one can study intriguing strong-coupling effects such as the emergence of localized cavity modes within the photonic bandgap.

The spin–momentum locking of Dirac surface states offers intriguing possibilities for converting between charge and spin currents. Experiments show that fine tuning of the Fermi level is critical for maximizing the efficiency of such conversions.

The interaction between the outflow of gas from a quasar and the interstellar medium can boost protons to relativistic energies. Collisions between such protons can explain a significant fraction of the unexplained extragalactic gamma-ray background.

The anomalous Hall effect is usually associated with ferromagnets but a large anomalous Hall response can be found in topologically non-trivial half-Heusler antiferromagnets thanks to Berry phase effects associated with symmetry breaking.

An experiment reports the unexpected behaviour of an object in uniform motion in superfluid helium-3 above the Landau critical velocity — the limit above which it can generate excitations at no energy cost.

The realization of a quantum kicked top provides evidence for ergodic dynamics and thermalization in a small quantum system consisting of three superconducting qubits.

Josephson plasma waves — electromagnetic waves propagating between layered superconductors — lie at the basis of a broad variety of phenomena. Now, parametric amplification of such waves has been shown by tuning the phase between pump and seed waves.

The elastic energy built up during peptide self-assembly is exploited in the realization of a microactuator. The energy stored is released on millisecond timescales via a buckling instability controlled with droplet microfluidics.

An intriguing state of matter known as a quantum spin liquid has been predicted to host Majorana fermions. A detailed theoretical and numerical analysis re-interprets existing Raman data for α-RuCl₃ and uncovers direct evidence of a fermionic response.

Relativistic Dirac fermions can be locally confined in nanoscale graphene quantum dots using electrostatic gating, and directly imaged using scanning tunnelling microscopy before escaping via Klein tunnelling.

Two distinct valleys in the electronic band structure of graphene provide an additional degree of freedom that could be exploited for devices. Conservation of this valley symmetry can now be seen in the quantized conductance of graphene nanoribbons.

Interacting quantum systems are expected to thermalize, but in some situations in the presence of disorder they can exist in localized states instead. This many-body localization is studied experimentally in a small system with programmable disorder.

Materials with low magnetic damping are important for a range of applications but are typically insulating, which limits their use. Thanks to a unique feature of the band structure, similar levels of damping can now be achieved in a metallic alloy.

The linear change in resistance with temperature in high-temperature superconductors is an enduring mystery. And now, the resistance in a magnetic field shows similar scaling, suggesting that physicists have another probe of the linear behaviour.

Scanning tunnelling spectroscopy provides access to the spatial variations in the strength of Rashba spin–orbit coupling in a two-dimensional electron system, with local fluctuations shown to cause spin dephasing.

The discovery of a superconducting temperature of roughly 200 K in hydrogen sulfide has attracted widespread attention. Now, the crystal structure of this system is elucidated experimentally.

A system in equilibrium takes a finite time to relax to a new equilibrium following a sudden change of a control parameter—impeding progress in device miniaturization. Now, a strategy succeeds in reducing this time for an open classical system.

Observing magnetic reconnection directly is generally difficult, but looking at the reconnection between erupting solar filaments and nearby coronal loops uncovers many fine details with unprecedented clarity.

Populations of growing yeast are shown to undergo a jamming transition typically observed in gravity-driven granular flows. The pressures generated by intercellular forces are found to be large enough to destroy the cells’ micro-environment.

An ultracold gas trapped in a symmetric double-well potential should populate both wells equally; however, the gas spontaneously localizes in one well when the interaction between atoms reaches a critical value, thus breaking parity symmetry.