We study the distribution of overlaps with the computational basis of a quantum state generated under generic quantum many-body chaotic dynamics, without conserved quantities, for a finite time $t$. We argue that, scaling time logarithmically with the system size $t \propto \log L$, the overlap distribution converges to a universal form in the thermodynamic limit, forming a one-parameter family that generalizes the celebrated Porter-Thomas distribution. The form of the overlap distribution only depends on the spatial dimensionality and, remarkably, on the boundary conditions. This picture is justified in general by a mapping to Ginibre ensemble of random matrices and corroborated by the exact solution of a random quantum circuit. Our results derive from an analysis of arbitrary overlap moments, enabling the reconstruction of the distribution. Our predictions also apply to Floquet circuits, i.e., in the presence of mild quenched disorder. Finally, numerical simulations of two distinct random circuits show excellent agreement, thereby demonstrating universality.

We generate a crystal of skyrmions in two dimensions using a Heisenberg Hamiltonian including the ferromagnetic interaction J, the Dzyaloshinskii-Moriya interaction D, and an applied magnetic field H. The ground state (GS) is determined by minimizing the interaction energy. We show that the GS is a skyrmion crystal in a region of (D, H). The stability of this skyrmion crystalline phase at finite temperatures is shown by a study of the time-dependence of the order parameter using Monte Carlo simulations. We observe that the relaxation is very slow and follows a stretched exponential law. The skyrmion crystal phase is shown to undergo a transition to the paramagnetic state at a finite temperature.

The moir\'e of twisted graphene bilayers can generate flat bands in which charge carriers do not posses enough kinetic energy to escape Coulomb interactions with each other leading to the formation of novel strongly correlated electronic states. This exceptionally rich physics relies on the precise arrangement between the layers.We survey published Scanning Tunnelling Microscope (STM) measurements to prove that near the magic angle, native heterostrain, the relative deformations between the layers, dominates twist in determining the flat bands. This is demonstrated at large doping where electronic correlations have a weak effect and where we also show that tip-induced strain can have a strong influence. In the opposite situation of low doping, we find that electronic correlation further normalize the flat bands in a way that strongly depends on experimental details.

We establish universal behavior in the anticoncentration properties of random quantum circuits, demonstrating its broad independence from the circuit architecture. Specifically, universality emerges in a certain scaling limit and extends beyond the leading order, incorporating subleading corrections arising from the finite system size $N$. We compute these corrections through exact calculations on ensembles of random tensor network states and corroborate the results with analytical findings in the random phase model. We then identify a heuristic framework for generic brickwork circuits, conjecturing the universality of these corrections. We further support our claim of anticoncentration universality through extensive numerical simulations, capturing the distribution of overlaps for systems up to $N = 64$ qudits and computing collision probabilities for systems up to $N \leq 1024$. Collectively, our results highlight the critical role of finite-size corrections and lead to a thorough understanding of the core phenomenology governing anticoncentration in quantum circuits.