Volume 21 Issue 6, June 2025

Students are turning to generative AI chatbots like ChatGPT to support their physics learning. Here, I examine one student’s interactions with ChatGPT on an exam recuperation assignment and the student’s reflections on the process.

The high precision of atomic sensors can be further enhanced by quantum correlations between atoms prepared in an entangled state through the use of artificial intelligence.

Quasicrystals were discovered by chance about 40 years ago, and it has largely been a matter of luck to find new ones since. Now, an approach has been found to grow colloidal quasicrystals by turning a dial while directly observing them with an optical microscope.

More than a hundred quasicrystals have been found so far, but their thermodynamic stability has remained an open question. Extrapolating density functional theory calculations of ever larger clusters now show that two alloys are indeed ground states.

Symmetry breaking is routinely observed in isolated systems, where perturbations propagate through the system. For out-of-equilibrium systems, however, perturbations are predicted to diffuse; and this key signature of spontaneous symmetry breaking has now been observed in a polariton quantum fluid.

A two-dimensional spectroscopic technique to probe the strength of electron–phonon coupling has the capability to simultaneously resolve the phonon mode and the electron transition energy — and is bringing fresh insight into the complex interactions of phonons and electrons in a range of materials.

Second messengers are intracellular signalling molecules that relay environmental changes and prompt cellular responses. Through an information-theory framework coupled with quantitative experiments, the second-messenger molecule cAMP, in the bacterium Pseudomonas aeruginosa, is shown to achieve information transmission rates of up to 40 bits per hour.

The status of plasma-based acceleration of electrons and positrons is discussed, with a focus on developing the positron arm of a plasma-based electron–positron linear collider.

The quantum simulation of driven, strongly correlated phases at large scales is challenging, primarily due to detrimental heating effects. Now, a large-scale interacting Mott–Meissner phase has been realized in a neutral atom quantum simulator.

Experiments with cold atoms in optical cavities are often limited to discontinuous operation due to reloading requirements. Now, continuous lasing is demonstrated with strontium atoms in a ring cavity, stabilized by atom loss mechanisms.

Simultaneous spin squeezing and the detection of dynamic fields is challenging as entanglement generation and signal interrogation often interfere. An experiment now demonstrates stable spin squeezing and field tracking in a hot atomic ensemble.

Spin models that can be emulated by quantum simulators are usually restricted to systems with conserved total magnetization. The tuning of photon-mediated interactions between atoms in a cavity enables the implementation of more general models also useful for quantum sensing tasks.

Gapless modes emerging from non-equilibrium phase transitions are predicted to diffuse rather than propagate as sound waves. Now, the diffusion of these modes and their suppression under symmetry breaking are confirmed in a polariton condensate.

Converting photons from one frequency range to another uses nonlinear effects that are often weak. Strong nonlinearities in rare-earth-ion-doped crystals have now been used to perform microwave-to-optical transduction at the single-photon level.

Crystallization processes are influenced by the presence of impurities. Colloid experiments now reveal two distinct types of growth mode that depend on the extent to which a crystallizing system can remove impurity particles from its growth front.

Control over electron populations in different conduction band minima in semiconductors can be used to store and process information. Now the ultrafast optical manipulation of such electrons at room temperature has been demonstrated in silicon and diamond.

Probing electron–phonon matrix elements in bulk materials is difficult. Now, an all-optical experimental approach is demonstrated that extracts phonon-mode- and electron-energy-resolved electron–phonon matrix elements in the bulk.

Despite exhibiting ferroelectric features, SrTiO₃ fails to display long-range polar order at low temperatures due to quantum fluctuations. An ultrafast X-ray diffraction experiment now probes polar dynamics of this material at the nanometre scale.

Quasicrystals, which lack translational symmetry but display rotational order, are difficult to make. Now an assembly method for the fabrication of colloidal quasicrystals that offers a high degree of controllability and reversibility is reported.

Quasicrystals lack translational symmetry but display rotational order. Whether antiferromagnetic order can exist in quasicrystals has been unclear. Now, long-range antiferromagnetic order is shown in the icosahedral quasicrystal Au₅₆In_28.5Eu_15.5.

Traditionally, density functional theory could not describe quasicrystals as they lack translational symmetry. An ab initio approach now establishes that the quasicrystalline structures of ScZn_7.33 and YbCd_5.7 are true ground states.

Skyrmion bags—textures comprising multiple skyrmions contained within a larger skyrmion—have been reported in several condensed matter systems. Now an optical analogue of these structures has been observed in plasmonic moiré superlattices.

Placing particles at the interface between immiscible fluids usually enhances emulsification. However, now it is shown that if the particles are ferromagnetic, emulsification is suppressed and a non-planar recoverable interfacial shape develops.

Blood flow through a vessel deforms vessel walls. Cells lining these walls sense the changes in pressure as blood flows and reorient their actin fibres in the direction of largest tension.

Bacterial second messengers carry signals from the environment to target proteins in the cell. Now the associated information transmission capacity is quantified and the optimal frequency to maximize it is determined.

Frictional motion of bodies in contact is facilitated by ruptures at their interface. Experiments with laboratory earthquakes now reveal that frictional ruptures at an interface can happen at both slow and fast timescales.

From monitoring sea-level changes at the millimetre-level to navigating through the streets of Gothenburg, Karine Le Bail discusses the need for precise positioning within well-defined 3D terrestrial and celestial reference frames.