Research Briefing

As counterparts to optical frequency combs, magnonic frequency combs could have broad applications if their initiation thresholds were low and the ‘teeth’ of the comb plentiful. Progress has now been made through exploiting so-called exceptional points to enhance the nonlinear coupling between magnons and produce wider magnonic frequency combs.

A practical and hardware-efficient blueprint for fault-tolerant quantum computing has been developed, using quantum low-density-parity-check codes and reconfigurable neutral-atom arrays. The scheme requires ten times fewer qubits and paves the way towards large-scale quantum computing using existing experimental technologies.

The concept of temporal mode-locking has been leveraged to study the interplay between laser mode-locking and photonic lattices that exhibit non-Hermitian topological phenomena. The results suggest new opportunities to study nonlinear and non-Hermitian topological physics as well as potential applications to sensing, optical computing and frequency-comb design.

Studies of a biological active nematic fluid reveal a spontaneous self-constraint that arises between self-motile topological defects and mesoscale coherent flow structures. The defects follow specific contours of the flow field, on which vorticity and strain rate balance, and hence, contrary to expectation, they break mirror symmetry.

In its superconducting state, MoTe₂ displays oscillations arising from an edge supercurrent, and when it is near niobium, there is an incompatibility between electron pairs diffusing from niobium and the pairs intrinsic to MoTe₂. Insight into this competition between pairs is obtained by monitoring the noise spectrum of the MoTe₂ supercurrent oscillations.

Predicting the complex flows that emerge in active fluid networks remains a challenge. A combination of experiments and theory was used to determine the hydraulic laws of active fluids. Analogies with frustrated magnetism and loop models explain the emergent flow patterns that result when active fluids explore pipe networks.

Subwavelength photonic gratings can host long-lived, negative-effective-mass photonic modes that couple strongly to electron transitions in constituent active materials. The resulting bosonic hybrid light–matter modes, or exciton-polaritons, can be optically configured to accumulate into various macroscopic artificial complexes and lattices of coherent quantum fluids.

Neutron spectroscopy, entanglement analysis, and simulations provide evidence that KYbSe₂ closely approximates a 2D quantum spin liquid. Although KYbSe₂ displays magnetic ordering at low temperatures, its magnetic dynamics are dominated by fractionalized excitations that exhibit anomalously large quantum entanglement, indicating that on finite timescales KYbSe₂ exhibits quantum spin liquid physics.

Landau’s theory of Fermi liquids predicts that impurities embedded in a Fermi sea of atoms form quasiparticles called polarons that interact with one another via the surrounding medium. Such mediated polaron–polaron interactions have been directly observed and are shown to depend on the quantum statistics of the impurities.

An approach combining single-cell imaging, agent-based simulations, and continuum mechanics theory is used to observe the effect of environmental stiffness on biofilm development. These measurements indicate that confined biofilms behave as active nematics, in which the internal organization and cell lineage are controlled by the shape and boundary of the biofilm.

Local thermodynamic measurements of a twisted transition metal dichalcogenide heterostructure reveal competition between unconventional charge order and Hofstadter states. This results from the presence of both flat and dispersive electronic bands, whose energetic ordering can be experimentally tuned.

Drops sitting on an array of parallel fibres spontaneously move along the fibres when subject to an airflow perpendicular to the array. The drops show long-range aerodynamic interactions with their downstream and upstream neighbours, and these can catalyse drop coalescence and removal of drops from the fibres — relevant for applications such as fog harvesting and filtration.

The collective dynamics observed between Bose-condensed atoms and molecules indicate the occurence of macroscopic quantum phenomena. Experimental investigations found that the atomic and molecular populations oscillate at a frequency that scales with the sample size, providing evidence for bosonic enhancement. These findings could make many-body quantum dynamics accessible in ultracold molecule research.

Using ‘momentum cooling’ in cyclotron-based proton therapy can increase proton transmission rates and thereby reduce treatment delivery times. This simple technique, which reduces the momentum spread of the proton beam without introducing substantial beam losses, enhances efficiency and has the potential to reduce costs, thereby advancing cancer treatment and improving patient outcomes.

Most quantum processors rely on native interactions between pairs of qubits to generate quantum entangling gates. Now, by modulating the driving laser fields, gates that entangle a triplet or quartet of trapped-ion qubits have been realized, creating useful new components for quantum computing applications.

A coherent interface between a mechanical oscillator and superconducting electrical circuits would enable the control of quantum states of mechanical motion, but such interfaces often result in excess mechanical energy loss. A new material-agnostic approach is shown to achieve strong electromechanical coupling while preserving a long phonon lifetime.

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.