Research Briefing in 2024

The nuclear pore complex of eukaryotic cells senses the mechanical directionality of translocating proteins, favouring the passage of those that have a leading mechanically labile region. Adding an unstructured, mechanically weak peptide tag to a translocating protein increases its rate of nuclear import and accumulation, suggesting a biotechnological strategy to enhance the delivery of molecular cargos into the cell nucleus.

Rotational symmetry is shown to protect the quadratic dispersion of out-of-plane flexural vibrations in graphene and other two-dimensional materials against phonon–phonon interactions, making the bending rigidity of these materials non-divergent. The quadratic dispersion is then consistent with the propagation of sound in the graphene plane.

The Q-value of electron capture in ¹⁶³Ho has been determined with an uncertainty of 0.6 eV c^–2 through a combination of high-precision Penning-trap mass spectrometry and precise atomic physics calculations. This high-precision measurement provides insight into systematic errors in neutrino mass measurements.

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.