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Cavity-stimulated Raman spin-flip emission is demonstrated by coupling a negatively charged InAs/GaAs quantum dot to a photonic crystal defect cavity. The emission is spectrally narrow and tunable over a range of about 125 GHz. The process can be made spin selective by tuning the scattered photons to be in resonance with the cavity.

Integrated single mode lasers capable of extremely narrow linewidths and high output power will enable precision portable quantum, microwave, and sensing applications. Here we demonstrate a simultaneous record low fundamental linewidth and high output power using an integrated Brillouin laser in a meter-scale silicon nitride coil resonator.

Optical cavities enhance light–matter interactions, and have been used to strongly couple a photon to a single spin. Here, the authors take this a step further by coupling a photon to a two-spin system by embedding an indium arsenide quantum-dot molecule in a photonic crystal cavity.

Deep, high-resolution polarization observations of HL Tau at 870  µm show gaps that have polarization angles with a notable azimuthal component and a higher polarization fraction than the rings.

Humanity’s Last Exam, a multi-modal benchmark at the frontier of human knowledge, is designed to be an expert-level closed-ended academic benchmark with broad subject coverage.

Iceberg calving can act as a submarine melt amplifier through excitation of transient internal waves.

Surface-enhanced Raman emission can measure the effective temperatures both of the vibrational modes and the flowing electrons in a nanoscale junction.

In this work the authors demonstrate on-chip integration of Brillouin lasing operating at visible wavelengths, with engineered design for stable output. This technical and scientific advance will help develop integrated light sources for quantum computing or atomic and molecular spectroscopy.

The efficiency of single junction solar cells is limited by their inability to absorb photons with an energy smaller than the bandgap. Here, the authors surpass the Shockley-Queisser limit by using an integrated hot-electron thermophotonic emitter to thermally up-convert sub-bandgap photons.

The work harnesses principles of spatial state tomography to fully characterise an optical beam in space, time, spectrum, and polarisation. Analysis of the output of a vertical-cavity surface-emitting laser illustrates the technique’s capabilities.

Using pancreatic organoids, Lee et al. show that the balance between epithelial tissue permeability-driven lumenal pressure and cell proliferation affects ductal morphogenesis.

Lead halide perovskite nanocrystals show size-tunable optical properties. Here the authors reveal a non-monotonic size dependence of exciton radiative lifetime, suggesting optimal sizes for applications requiring fast photoemission.

Laryngeal lesions can be endoscopically detected with high sensitivity and in real time by measuring differences in the polarization signatures between cancerous and healthy tissues.

Brillouin lasing with 0.7 Hz fundamental linewidth is observed by optically exciting a monolithic bus–ring Si₃N₄ waveguide resonator. The Brillouin laser is applied to an optical gyroscope and a low phase-noise photonic microwave oscillator.

CaBLAM is a bioluminescent genetically encoded calcium indicator that delivers high-contrast signals as shown in cell culture, in the in vivo mouse brain and in zebrafish larvae.

Pulmonary type 2 inflammation is associated with type 2 innate lymphoid cells. Here the authors use the Collaborative Cross mouse panel to show that ILC2 abundance during type 2 lung inflammation is different across the panel and identify free-fatty acid receptor 3 (Ffar3) as a gene responsible and show cytokine and ILC2 functional changes.

Photoexcitation of quadrupolar dyes—key materials for various optoelectronic applications—induces an excited-state symmetry-breaking charge-transfer process with unknown microscopic origin. Now it has been shown that vibronic coupling to high-frequency backbone modes drives the initial ultrafast symmetry breaking before solvation, distinguishing fundamental intramolecular dynamics from solvent-induced charge localization.

Upconversion particle-based holographic fluorescence optical tweezers enable super-resolved photonic force microscopy and applications on long-range subfemtonewton force sensing, intracellular viscosity measurements and temperature sensing.

Engineering strain in semiconductor structures provides additional control over the optical and electronic properties, which is promising for device applications. Fluegel et al. show that electronic Raman scattering provides a route to sensitively measure the degree of strain in thin semiconductor layers.

Many split inteins suffer from poor efficiency in protein trans-splicing, limiting protein engineering applications. Here, authors identify soluble β-sheet-dependent precursor aggregates as the cause, and subsequently use rational mutagenesis to obtain a cysteine-less split intein with full activity.

Near-infrared (NIR) fluorophores have attracted interest for bioimaging; yet availability, biocompatibility and application can be an issue. Here, the authors report on the development of Egyptian Blue nanosheets with high NIR fluorescence and photostability demonstrating bioimaging applications in vivo.

Pore-forming toxins are expressed as monomers and assemble into multimeric pores. Here, Benke et al. follow the kinetics of pore formation for the bacterial toxin ClyA with single-molecule methods and show that pore formation progresses through the assembly of oligomeric intermediates, rather than by the addition of monomers to a nascent pore.

Chronic care manages long-term, progressive conditions, while acute care handles short-term ones. Here, authors show chronic conditions account for most of the global health burden, with 68% of DALYs and 93% of YLDs attributed to chronic care needs.

Retarder arrays enable advanced photonic applications but are limited by controllable flexibility. Here, authors demonstrate a compound modulator that creates synthetic tuneable retarder arrays, offering unprecedented dynamic control of light, enabling new beam generation, analysis, and correction.

Nanofluidic scattering microscopy enables label-free, quantitative measurements of the molecular weight and hydrodynamic radius of biological molecules and nanoparticles freely diffusing inside a nanofluidic channel.

Microfluidic systems controlled by a single driving pressure are programmed to exhibit complex flow-switching schemes and a fluid analogue of Braess’s paradox by exploiting fluid inertia and network design.

Membrane contact sites (MCS) are subcellular regions where two organelles appose their membranes to exchange small molecules, including lipids. Here authors designed an in vitro MCS suitable for cryotomography and sub-tomogram analysis which sheds light on the recruitment of proteins of different sizes within MCS of adjustable thickness.

Pump–probe measurements conventionally achieve femtosecond time resolution for X-ray crystallography of reactive processes, but the measured structural dynamics are complex. Using coherent control techniques, we show that the ultrafast crystallographic differences of a fluorescent protein are dominated by ground-state vibrational processes that are unconnected to the photoisomerization reaction of the chromophore.

Experiments and numerical modelling of dilute pyroclastic currents reveal an internal amplification of the dynamic pressure, which suggests that flow-building interactions are stronger when multiphase flow dynamics are accounted for.

Emission levels useful for applications from upconversion nanoparticles require high laser irradiance. Here, Liang et al. exploit the superlensing effect from dielectric microbeads to enhance the luminescence efficiency of upconversion nanoparticles and show its application for optogenetics.

The authors show how to compute the autocorrelation function of FRET efficiencies and obtain dynamic information from as little as a few thousand molecules.

Spatial beam clean-up and spatiotemporal modulation instability in graded-index multimode fibres are studied in a regime characterized by disorder, nonlinearity and dissipation.

The fast radio burst FRB 20180916B repeats with a periodicity of 16 days, and is now found to emit down to a frequency of 120 MHz, much lower than previously observed.

Oblique line scan microscopy achieves nanoscale spatial and sub-millisecond temporal resolution across a large field of view, enabling improved and robust single-molecule biophysical measurements and single-molecule tracking in both cells and solution.

NMR and Raman spectroscopies pinpoint the role of the protein droplet surface and RNA in the liquid droplet maturation mechanism of the FUS protein. A crust-like β-sheet structure is formed on the surface of FUS droplets during aging.

Colloidal aggregates are conventionally formed by particle aggregation under thermal fluctuation. Now the structure and mechanical properties of aggregates can be controlled by an active bath of swimming Escherichia coli.

A sensitive Breakthrough Listen search for technosignatures towards Proxima Centauri has resulted in a viable narrowband signal. The observational approach, using the Parkes Murriyang telescope, is described here, while the signal of interest is analysed in a companion paper by Sheikh et al.

In situ detection of protein coronas is usually performed via optical methods, but light scattering may hamper these measurements. Here, the authors use diffusion NMR techniques to characterize protein corona formation on ¹⁹F-labeled nanoparticles in blood and other complex media.

The large-scale analysis of neural cell reconstructions provides a base line for morphological characteristics, and informs diffusion MRI modelling.

One way to describe a particle is as a localised, 3-dimensional topological state, such as a skyrmion or hopfion. Here, the authors demonstrate and characterise particle-like skyrmionic hopfions in a free-space structured light beam.

Far-infrared polarimetric observations reveal a transition parallel to the gas flow in the orientation of magnetic field lines in the Serpens South molecular cloud, allowing gravitational collapse to occur even in the presence of strong magnetic fields.

The interplay between coherent wave-like and incoherent particle-like transport can lead to environment-assisted quantum transport. Using time resolved microscopies and theoretical modeling, the authors show signatures of this enhanced transport regime in perovskite nanocrystal superlattices.

Biomolecular condensates play a role in cellular processes and their size affects reaction pathways. The size distribution is connected to varying contributions of nucleation and coalescence.

Metasurfaces allow for vast possibilities of light control. Here, the authors demonstrate on-demand engineering and realization of a broad family of two-dimensional phase singularity sheets and transverse polarization singularity sheets, opening up new aspects of light-matter interaction.