condensed-matter

While chemical bonds usually determine the structure and properties of a material, bonds between neighboring metal atoms can also change as temperature or other conditions change. These changes can lead to unusual electronic and magnetic behaviors. A new study on Li₀.₅VS₂ shows that bonding between vanadium atoms can reorganize as the material passes through successive […]

In nonlinear classical field theories that admit localized or topological solutions (for example, Skyrme-type or Faddeev–Skyrme-type models), what mathematical and numerical evidence is normally considered sufficient to distinguish a genuinely stable localized solution from a stationary... Read more

I have been dabbling a little with using AI (at a very basic level) to help me with some research problems. For example, in a recent preprint, I did the maths in the Appendix with help from AI. I am curious to hear from the experience of others of using it for research in condensed matter theory and theoretical chemistry. Peter Woit made a similar request to the high-energy theory community. The …

Magnons now move slower than previously calculated due to an unexpected ‘dressing’ by surrounding quantum particles, revealing a direct link between speed and unseen entanglement. Increasing on-site repulsion weakens this connection and diminishes any resulting paired states formed when magnons interact. This offers a new way to probe these correlations via measurable velocity deficits without di…

In particle physics I am used to the Feynman propagator being decomposed into positive and negative frequency Wightman functions. For example, this is the representation used in Eq. (6.2.13) of Weinberg's volume I [1]. In his notation, \begin{equation} -\mathrm{i} \Delta_{\text{F}}(x) = \theta(x) \Delta_+(x) + \theta(-x) \Delta_+(-x) \end{equation} This is constructed to have only positive freque…

Dense frustration typically forces systems into disordered ‘glassy’ states, but simulations now demonstrate an alternative outcome: a continuous loss of global compatibility that maintains finite integrated adjacent correlation weight. This unexpected behaviour reveals a “correlated gauge liquid” where networks retain order even under extreme disruption. Unlike conventional models, this system av…

This question regards Ewing's molecular theory of magnetism . I.) Ewing's molecular theory of magnetism describes every magnetic substance as being a collection of dipoles that are initially in a state where there is no specific and uniform orientation as a result of the application of a magnetic field and because of this the net magnetic field strength of the substance becomes zero. Now, let us …

I know that tight-binding graphene with $\text{p}_\text{z}$ -, $\text{d}_\text{xz}$ - and $\text{d}_\text{yz}$ -orbitals and spin-orbit coupling is a $\mathbb{Z}_2$ -topological insulator. But I want to categorise it according to the periodic table of topological invariants . My problem now is that I don't know which of the ten Altland-Zirnbauer classes is the correct one. Based on my logic, it h…

Nature Communications, Published online: 10 September 2026; doi:10.1038/s41467-026-77528-7 Flat-band localization and non-Hermitian skin effects are well known features in modern physics, yet the interplay between the two is often poorly characterised. Here, the authors focus on 1D and quasi−1D lattices with tunable non-reciprocal hopping terms, experimentally realized with topoelectrical circuit…

Nature Physics, Published online: 10 September 2026; doi:10.1038/s41567-026-03444-8 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 Physics, Published online: 10 September 2026; doi:10.1038/s41567-026-03434-w Ferrons are the quasiparticles associated with the collective excitations of spontaneous polarization. External electric fields have now been shown to tune their properties in a nonvolatile manner.

We already have quantum computers, but they're highly specialized, not particularly practical, and only cover...

Synchrotron diffraction reveals a hexagonal oxygen lattice in water ice above 200 gigapascals, although the mobile-hydrogen state is inferred rather than directly imaged.