Volume 16 Issue 7, July 2020

Equilibrium self-assembly processes find free-energy minima but no such general statement holds for systems driven out of equilibrium. A new study has employed laser-induced convective flows to achieve dissipative self-assembly across multiple scales with universal growth and fluctuation statistics.

Quantum cascade lasers are bright and compact semiconductor lasers that emit light in the mid- to far-infrared spectral region. The use of a closed ring cavity has now set them on the path towards ultrafast pulses.

Squeezed light is useful for metrology and quantum information. An optomechanical squeezed light source that works at room temperature will facilitate the technological applications of quantum light.

Pairs of electrons can form above the superconducting critical temperature. The authors review the similarities and differences in this phenomenology in copper-based superconductors and oxide heterostructures.

Hybrid devices of superconductors and semiconductor nanowires may be topological and host majorana. This Perspective summarizes the current situation of the field, and highlights the developments in materials science required to make progress.

The identification of superconductivity and strong interactions in twisted bilayer 2D materials prompted many questions about the interplay of these phenomena. This Perspective presents the status of the field and the urgent issues for future study.

The breakdown of superconductivity is described as a reduction in the amplitude of the order parameter or a breakdown in phase coherence of Cooper pairs. This Review Article highlights recent results that show both mechanisms may be at play simultaneously.

Boundary-localized bulk eigenstates given by the non-Hermitian skin effect are observed in a non-reciprocal topological circuit. A fundamental revision of the bulk–boundary correspondence in an open system is required to understand the underlying physics.

Electron spins in solid usually relax their energy through the coupling with phonons in the host lattice. By using the coupling to microwave photons in a cavity as an alternative relaxation path, it is demonstrated that spins can be cooled below the lattice temperature.

Compton scattering experiments off helium atoms for photon energies close to the ionization threshold reveal that electrons are not only emitted in the direction of the momentum transfer but also backwards.

Measurements of non-Hermitian photon dynamics show boundary-localized bulk eigenstates given by the non-Hermitian skin effect. A fundamental revision of the bulk–boundary correspondence in open systems is required to understand the underlying physics.

Generalization of linear response theory to the non-Hermitian case turns dissipation into a new tool for detecting equilibrium phases. The prediction from this theory remarkably agrees with a recent cold atom experiment.

By exploiting the long-lived phonon modes in nanoscale mechanical resonators, a quantum memory that operates around the standard telecom wavelength of 1,550 nm is realized on a silicon platform.

Ionization delays from ethyl iodide around a giant dipole resonance are measured by attosecond streaking spectroscopy. Using theoretical knowledge of the iodine atom as a reference, the contribution of the functional ethyl group can be obtained.

The ability to create optomechanically squeezed light at room temperature across a frequency range in the audio band could improve the measurement precision of future interferometric detectors for gravitational waves.

An exotic s + is multiband superconducting state manifests in a doped pnictide superconductor when a second band moves below the Fermi surface. This creates an internal magnetic field, breaking time-reversal symmetry.

Biological systems are able to self-assemble in non-equilibrium conditions thanks to a continuous injection of energy. Here the authors present a tool to achieve non-equilibrium self-assembly of synthetic and biological constituents with sizes spanning three orders of magnitude.

Collective cell migration is usually attributed to large-scale transmission of signals through cell junctions. Here, the authors confine cells into a ring-shaped pattern and show that collective cell migration can arise at the single-cell level.

Experiments realizing the indirect-drive fast ignition scheme for inertial confinement fusion are reported. Enabled by a tightly compressed target, an increase of neutron yield is observed.

When you start tearing a piece of aluminium foil apart, you create dislocations in the material. Suhas Eswarappa Prameela and Tim Weihs recount the story of the Burgers vector that is now an indispensable tool for describing dislocations.