This month we celebrate Nature Physics' twentieth birthday, consider the flexoelectricity of water ice, and feature a Perspective on chiral phonons. Have a look at go.nature.com/NPoct25

A trion fluid—which forms when excitons bind to an extra electron or hole—is expected to exhibit a Hall effect in magnetic fields. Now, this is demonstrated in electron–hole double layers. nature.com/articles/s41567-0…

Random access memory is an important element of classical computers, but equivalent schemes for quantum computers are much less mature. Now an eight-qubit random access memory has been demonstrated using superconducting circuits. nature.com/articles/s41567-0…

By combining quantum and relativistic physics, it is possible to verify someone’s position remotely without needing to trust them. Such a position verification protocol has now been introduced and demonstrated with a quantum optics experiment. nature.com/articles/s41567-0…

Altermagnetic states hold promise for spintronic applications but are yet to be observed in twisted van der Waals materials. Now an orthogonally twisted CrPS₄ homostructure is shown to exhibit signatures of altermagnetism. nature.com/articles/s41567-0…

Driving a solid with light can create a topological insulator, but controlling its electrons has remained elusive. Optical control of electrons in a Floquet topological insulator has now been achieved in light-dressed graphene. nature.com/articles/s41567-0…

Understanding the non-equilibrium dynamics of ferrons—collective excitations of electric polarization—is crucial for device applications. Now electric-field control of coherent ferron oscillations is demonstrated in a layered ferroelectric. nature.com/articles/s41567-0…

Moiré excitons have been widely observed in twisted two-dimensional semiconductors but have not been directly imaged at room temperature. Now, this is achieved using photocurrent atomic force microscopy. nature.com/articles/s41567-0…

Zebrafish can regenerate amputated fins back to their original size. It is now shown that gradients in extracellular signal-regulated kinase activity act as rulers during fin bone regeneration. nature.com/articles/s41567-0…

Creation and annihilation of topological defects are prevalent in active materials. It is now shown that in living systems with nematic order, polar propulsion breaks mirror symmetry during these processes. doi.org/10.1038/s41567-026-0…

A transport technique that allows the measurement of the effective charge of fractional quantum Hall states as they tunnel through a controlled impurity is demonstrated. nature.com/articles/s41567-0…

The location of the melting curve of diamond is unclear. Now, this is illuminated with shock compression experiments that provide strong evidence for shock-induced melting. nature.com/articles/s41567-0…

Preparation of thermal and ground states is needed for a number of quantum algorithms but is generally computationally difficult. Now state preparation algorithms with efficiency guarantees have been developed for an important class of model. nature.com/articles/s41567-0…

Systems of coupled self-propulsive components, both biological and synthetic, display coordinated dynamics. Experiments with 3D printed motors now show that rotary motion can lead to spatiotemporal order as well as disorder-induced wave propagation. nature.com/articles/s41567-0…

Wigner crystals have been observed in transition metal dichalcogenides, but their collective excitations have not been shown. Now the signatures of these excitations are revealed in the optical spectra of a charge-tunable monolayer semiconductor. nature.com/articles/s41567-0…

Wigner crystals have been observed in 2D semiconductors, but their internal dynamics have been largely inaccessible. Now this is demonstrated in a monolayer semiconductor. nature.com/articles/s41567-0…

Understanding the time-resolved dynamics of antiferromagnetic skyrmion interactions remains a challenge, limiting control over their collective behaviour. Now their ultrafast dynamics is visualized in real time in thin-film multilayers. nature.com/articles/s41567-0…

Analysis of the mechanical properties of mitotic chromosomes is key for understanding the robustness of chromosomes during cell division. It is now shown that chromosomes are highly mechanically heterogeneous. nature.com/articles/s41567-0…

Altermagnetism has been experimentally demonstrated in fermionic systems, but not yet in photonic systems. Now it is observed in a magnetophotonic crystal. nature.com/articles/s41567-0…

Elastic stresses are believed to play a role in the vitrification process in glasses, but measuring them is challenging. Imposing elastic boundary conditions is now shown to provide a way to probe elastic effects within glassy samples. nature.com/articles/s41567-0…

Dualities between different models are an important tool in theoretical many-body physics. Here a constructive recipe is given for topological interfaces between dual models that are transparent to wavepackets but alter their properties. nature.com/articles/s41567-0…