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Recent developments in advanced light sources have made it possible to transiently alter the electronic properties of materials by exciting specific atomic vibrations in solids. This study provides a theoretical framework for these experiments.

Integrating an electronic device with a cavity can cause the electrons to couple to photons strongly enough to form hybrid modes. Now, the cavity effects induced by intrinsic graphite gates are shown to modify the low-energy properties of graphene.

The authors image non-equilibrium exciton phase-transition dynamics in moiré superlattices, revealing how strong long-range dipolar repulsion freezes the motion of the Mott insulator over a timescale of tens of nanoseconds.

Twisted van der Waals systems are known to host flat electronic bands, originating from moire potential. Here, the authors predict from purely geometric considerations a new type of nearly dispersionless bands in twisted bilayer MoS₂, resulting from destructive interference between effective lattice hopping matrix elements.

Studies of twisted bilayer transition metal dichalcogenides have so far focused only on those containing group-VI metals. Here, the authors predict that twisted bilayers of ZrS₂, with the group-IV metal Zr, form an emergent moiré Kagome lattice with a uniquely strong spin-orbit coupling, leading to quantum-anomalous-Hall and fractional-Chern-insulating states.

The authors present electrical transport-based evidence of generalized Wigner crystal states in twisted bilayer MoSe₂ at fractional electron fillings ν = 2/5, 1/2, 3/5, 2/3, 8/9, 10/9, and 4/3, together with a Mott state at ν = 1. They further demonstrate continuous quantum melting transitions in a multi-parameter space of electron density, displacement and magnetic fields.

Γ and K valleys in twisted transition metal dichalcogenides have emerged as highly tunable knobs for accessing different correlated electronic states in solid-state devices. Here, the authors tune a Mott-Hubbard state to a charge-transfer insulator state in twisted double-bilayer WSe₂.

Twisting the relative orientation of the sheets in few-layer van der Waals materials can cause drastic changes in the electronic bandstructure. Here, the authors predict that twisted bilayer GeSe realises an effective one-dimensional flat-band electronic system with exotic, strongly correlated behaviour.

Moiré heterostructures have latterly captured the attention of condensed-matter physicists. This Review Article explores the idea of adopting them as a quantum simulation platform that enables the study of strongly correlated physics and topology in quantum materials.

The authors theoretically propose a simple microscopic mechanism for light-induced superconductivity based on a boson coupled to an electronic interband transition. The electron-electron attraction needed for the superconductivity can be resonantly amplified when the boson’s frequency is close to the energy difference between the two electronic bands. The model can be engineered using a 2D heterostructure.

In moiré materials, structural relaxation phenomena can lead to unexpected and novel material properties. Here, the authors characterize an unconventional non-local relaxation process in twisted double trilayer graphene, in which an energy gain in one domain of the moiré lattice is paid for by a relaxation that occurs in the other.

Here, a combined experiment-theory framework based on different nano-imaging techniques and first-principle calculations is used to analyse the shapes of moiré patterns in twisted van der Waals structures, enabling an accurate description of the coupling between the atomically thin layers.

Superconductivity reported in metals driven away from equilibrium via optical pumping has been proposed to arise from nonlinear coupling between electrons and optically excited phonons. The authors use an exact approach to show that here, disorder, which disfavors superconductivity, emerges even though the system is translationally invariant.

Observations of an electronic nematic phase in twisted double bilayer graphene expand the number of moiré materials where this interaction-driven state exists.

Tunable correlated states are observed in twist bilayer WSe₂ over a range of twist angles, with signatures of superconductivity for a twist of 5.1°.

The authors employ Quantum Monte Carlo simulations to study the scaling behavior of the magnetic structure factor and other observables in a 2D quantum critical magnet coupled to a single cavity mode. They find that while the quantum critical point remains unchanged, critical fluctuations are significantly enhanced and a fractional scaling exponent deviates from expectations based on perturbation theory.

For solid-state experiments, exactly solvable quantum light matter models, where the quantum nature of light is relevant, are scarce. Here, the authors introduce an exactly solvable model, where a one-dimensional tight-binding chain is coupled to a single cavity mode and derive analytic expressions for the ground state, where the photons are squeezed due to the light-matter coupling.

The mechanism behind the transient emergence of superconductivity upon irradiation with light in some materials is highly debated, which is in part due to the strong correlations at play. Here, the authors investigate the dynamical emergence of superconductivity in the strongly correlated, yet exactly solvable, Yukawa-Sachdev-Ye-Kitaev model and discuss differences and similarities to the relaxation dynamics of conventional superconductors.

Scanning tunnelling spectroscopy is used to map the atomic-scale electronic structure of magic-angle twisted bilayer graphene, finding multiple signatures of electron correlations and thus providing insight into the sought-after mechanism behind superconductivity in graphene.