Research Briefing

Repeated firing of vortex rings into a water tank is shown to create an isolated blob of confined turbulence — perfect for studying the nature of turbulence and its interface with quiescence. Moreover, using coherent vortex rings to feed the turbulence allows the controlled injection of conserved quantities such as helicity.

An experimental platform comprising two disordered superconductors separated by a thermally conducting electrical insulator represents a controllable physical system of interdependent networks. This system is modelled by thermally coupled networks of Josephson junctions. This platform could provide insights into theoretical multiscale phenomena, such as cascading tipping points or self-organized branching processes.

It’s a long-standing theoretical prediction that mutual information in locally interacting, many-body quantum systems follows an area law. Using cold-atom quantum-field simulators on an atom chip to measure the scaling of von Neumann entropy and mutual information, that prediction is now proved true.

Time crystals are a new state of matter. Conventional crystal properties are periodic in space, while the properties of a time crystal are periodic in time. A continuous quantum time crystal has recently been realized, and now, using optically driven many-body interactions in a nano-mechanical photonic metamaterial, a classical continuous time crystal has been created.

Photon bound states are quantum states of light that emerge in systems with ultrahigh optical non-linearities. A single artificial atom was used to study the dynamics of these states, revealing that the number of photons within the pulse determines the time delay after the pulse scatters off the atom.

Controlling the spatial distribution of optically active spin defects in solids is a long-standing goal in the quantum sensing and simulation communities. Measurements of the many-body noise generated by the spins were used to verify that a highly coherent and strongly interacting quantum spin system was confined to two dimensions within a diamond substrate.

A DNA-based nanorobotic arm connected to a base plate through a flexible joint can be used to store and release mechanical energy. The joint acts as a torsion spring that is wound up by rotating the arm using external electric fields and is released using a high-frequency electrical pulse.

Coherent multidimensional spectroscopy with nanoscale spatial resolution was used to directly probe a plasmon polariton quantum wave packet. To reproduce these results an improved quantum model of photoemission was required, in which the coherent coupling between plasmons and electrons is accounted for with the plasmon excitations extending beyond a two-level model.

An atomic Bose–Fermi mixture was driven through a quantum phase transition by varying an applied magnetic field to tune the interspecies interactions. This approach enabled the efficient generation of sodium–potassium molecules in the quantum degenerate regime.

Measurements of the switching supercurrent statistics of a superconducting quantum interference device based on bismuth, a second-order topological insulator, reveal that excited Andreev states are surprisingly long-lived. This protection can be attributed to the splitting of the Andreev pairs carrying the supercurrent along separate crystal hinges of opposite helicities.

The critical temperature of a high-temperature superconductor was systematically tuned using an ionic-liquid gating technique. Measurements of this system revealed a universal quantitative relationship between superconductivity and the strange-metal state, which gives insight into the mechanism responsible for high-temperature superconductivity.

Organs in the human body have complex networks of fluid-filled tubes and loops with different geometries and topologies. By studying self-organized, synthetic tissues, the link between topological transitions and the emergence of tissue architecture was revealed.

The spatiotemporal profile of the electric field around a high-energy electron beam was visualized using an ultrafast technique based on electro-optic sampling. By investigating the formation of the Coulomb field it was possible to experimentally confirm the validity of the predictions of special relativity regarding electromagnetic fields.

An ultracold spinor Bose gas was used to achieve advanced experimental control and detection of an easy-plane ferromagnet, allowing observation of the system as it approaches equilibrium. The measurements revealed twofold superfluidity in the spin and density degrees of freedom with very different critical speeds.

Measurements of a transversely polarized target were used to probe the spin structure of the proton in the low-energy region where the interactions between the quarks cannot be ignored. These results provide a benchmark for testing our understanding of the strong force.

The formation of bubbles at liquid–liquid interfaces is challenging to explain because gas pockets cannot be stabilized by cracks on solid impurities. Experiments show that a difference in the gas solubilities of two immiscible liquids provides a gas reservoir, which allows gas to accumulate at the interface, leading to bubble formation.

Evidence for an exotic form of the Kondo effect has been obtained by placing magnetic atoms on single-layer 1T-TaSe₂, which is a quantum spin liquid candidate. Unlike conventional Kondo screening, which arises from conduction electrons in a metal, the Kondo effect in 1T-TaSe₂ arises from charge-neutral particles known as spinons.

A proposed materials design principle can facilitate the discovery of strongly correlated topological semimetals. It predicts promising candidate materials by cross referencing theoretical models based on realistic crystal structures with a materials database. This approach is verified by synthesizing and experimentally investigating a proposed material.

Attosecond charge migration in a neutral molecule has been observed to decohere within approximately 10 fs. However, this does not mean that the electronic coherence is irreversibly lost, as the charge migration is observed to revive after 40–50 fs. These findings have the potential to enable laser control of photochemical processes.