Reviews & Analysis

Light emitted near an optical waveguide is captured and equally split into two modes with opposite directions of propagation. By controlling the dipole spin of the emitter, it is possible to break this symmetry and select only one direction.

Fractional magnetic excitations naturally emerge in one-dimensional spin chains. The search for fractionalization in higher dimensions has focused on frustrated systems but evidence now suggests that it can occur in simple two-dimensional antiferromagnets.

Transferring electrons from the ground state to an excited state by optical pumping usually increases the population of the upper state. But for graphene in an external magnetic field, the pumped state actually gets depleted.

In 2006, Nature Physics published a paper reporting a Stern–Gerlach effect for dark polaritons and one revealing the existence of slow-light solitons. Both of these papers have significantly advanced the field of slow-light research.

Graphene is a candidate spintronics material, but its weak intrinsic spin–orbit coupling is problematic. Intercalating graphene on an iridium substrate with islands of lead is now shown to induce a strong, spatially varying spin–orbit coupling.

Subradiant states have remained elusive since their prediction sixty years ago, but they have now been uncovered in ultracold molecules, where they could prove useful for ultra-high precision spectroscopy.

Magnetic fields can be used to modify light absorption in chiral media, but the effect is weak, so the potential of this approach has gone largely untapped. Synchrotron radiation may provide a solution, enabling surprisingly strong dichroisms in a molecular helix.

Ferroelectric polarization vortices close to a ferroelectric transition turn out to be striking models of the cosmos in which strings are thought to have condensed out of the rapid expansion of the early Universe.

The on-line isotope separation technique for the production of accelerated beams of radioactive ions has led to important advances in our understanding of atomic nuclei. These are now reviewed, and further prospects are discussed.

Dark matter remains experimentally elusive. But what if it is more classical than expected, resembling a spatially varying field? A network of atomic clocks would be able to detect its variations.

Non-reciprocal components are useful in microwave engineering and photonics, but they are not without their drawbacks. A compact design now provides non-reciprocity without resorting to magnets or nonlinearity.

Stretching a sheet of graphene could induce a superconducting state. Similar strain-induced superconductivity may be realized at the interface between a topological crystalline insulator and a trivial band insulator.

Solitons in attractive Bose–Einstein condensates are mesoscopic quantum objects that may prove useful as tools for precision measurement. A new experiment shows that collisions of matter-wave bright solitons depend crucially on their relative phase.

Exciton–polaritons, resulting from the light–matter coupling between an exciton and a photon in a cavity, form Bose–Einstein-like condensates above a critical density. Various aspects of the physics of exciton–polariton condensates are now reviewed.

The old adage that you can't tango alone is certainly true for humans. But recent experiments show that it may also be applicable to Rydberg atoms, which keep a beat through the coherent exchange of energy.

Rapidly changing noise impedes high-fidelity quantum control. An engineering framework for predicting and mitigating such dynamics has now been validated, revealing physical insights into the time evolution of quantum states.

Astrophysical observations of Hawking radiation may be out of reach, but evidence for the self-amplification of Hawking radiation has now been observed in a sonic analogue of a black hole.

A microcavity device operating in the strong light–matter interaction regime can produce coherent perfect absorption of photons — providing a viable system for the perfect feeding of polaritons.

The ability to harness spin polarization is critical for many semiconductor spin devices. It now seems that spin–orbit coupling with locally broken symmetry can enable a giant spin polarization in a semiconductor that is otherwise inversion symmetric.