Excitation of long-lived states in bromine nuclei using a tabletop laser-plasma accelerator providing pulsed ($<100\mathrm{fs}$) electron beams provided a sensitive probe of $\gamma$ strength and level densities in the nuclear quasicontinuum and may indicate angular momentum coupling through electron-nuclear interactions. Solid-density active ${\mathrm{LaBr}}_3$ targets absorb real and virtual photons up to $35\pm 2.5\mathrm{MeV}$ and deexcite through $\gamma$ cascade into different states. A factor of $4.354\pm 0.932$ enhancement of the ${}^{80}{\mathrm{Br}}^m{/}^{80}{\mathrm{Br}}^g$ isomeric ratio was observed following electron irradiation, as compared to bremsstrahlung. Additional angular momentum transfer could possibly occur through nuclear-plasma or electron-nuclear interactions enabled by the ultrashort electron beam. Further investigation of these mechanisms could have far-reaching impact including decreased storage of long-term nuclear waste and an improved understanding of heavy element formation in astrophysical settings.

We find the turbulent energy spectrum of weakly interacting 2D internal gravity waves using the full, nonhydrostatic dispersion relation. This spectrum is an exact solution of a regularized kinetic equation, from which the zero-frequency shear modes have been excised by a careful limiting process. This is a new method in wave kinetic theory. The turbulent spectrum agrees with the 2D oceanic Garrett-Munk spectrum for frequencies large compared to the Coriolis frequency and vertical scales small compared to the depth of the ocean. We show that this turbulent spectrum is the unique power law solution to the steady kinetic equation with a nonzero radial flux. Our solution provides an interesting insight into a turbulent energy cascade in an anisotropic system—like isotropic turbulence it is self-similar in scale, but its angular part is peaked along the curve of vanishing frequency and is self-similar in frequency.

The intrinsic Helmholtz free-energy functional, the centerpiece of classical density functional theory, is at best only known approximately for 3D systems. Here we introduce a method for learning a neural-network approximation of this functional by exclusively training on a dataset of radial distribution functions, circumventing the need to sample costly heterogeneous density profiles in a wide variety of external potentials. For a supercritical Lennard-Jones system with planar symmetry, we demonstrate that the learned neural free-energy functional accurately predicts inhomogeneous density profiles under various complex external potentials obtained from simulations.

Twisted heterostructures of two-dimensional crystals can create a moiré landscape, thereby changing the properties of its parent crystals. Here, the alternated stacking of posttransition metal monochalcogenides and transition metal dichalcogenides in misfit layer compound crystals is used as a moiré generator. X-ray diffraction shows the presence of twins with a small twist angle between them. The surface electrical potential from the induced sliding ferroelectricity is seen by using scanning probe microscopy and electron microscopy with domain sizes up to tens of micrometers.

Quantum control techniques play an important role in manipulating and harnessing the properties of different quantum systems, including isolated atoms. Here, we propose to achieve quantum control over a single on-surface atomic spin using Landau-Zener-Stückelberg-Majorana (LZSM) interferometry implemented with scanning tunneling microscopy (STM). Specifically, we model how the application of time-dependent, nonresonant ac electric fields across the STM tip-surface gap makes it possible to achieve precise quantum state manipulation in an isolated ${\mathrm{Fe}}^{2+}$ ion on a $\mathrm{MgO}/\mathrm{Ag}(100)$ surface. We propose a protocol to combine Landau-Zener tunneling with LZSM interferometry that permits one to measure the quantum spin tunneling of an individual ${\mathrm{Fe}}^{2+}$ ion. The proposed experiments can be implemented with ESR-STM instrumentation, opening a new venue in the research of on-surface single spin control.

We formulate a generalized $D$-dimensional field theory, parametrized by an $O(d)\times O(D)$ tensor field with an energetic longitudinal constraint, describing a new class of fluctuating “tattered” membranes, exhibiting a nonzero density of topological connectivity defects—slits, cracks, and faults at an effective medium level. For infinite-coupling constraint, the model reproduces the elastic membrane, with its rich anomalous elasticity realized by, e.g., graphene. Two additional fixed points emerge within the critical manifold: (i) globally attractive, “isotropic” $O(d)\times O(D)$, and (ii) “transverse,” which in $D=2$ is the exact “dual” of the elastic membrane. Their properties are obtained in general $D$, $d$ from the renormalization group and the self-consistent screening analyses. They correspond to critical points of an interesting class of constrained spin models.

Recently, we proposed a universal scaling framework that shows shear thickening in dense suspensions is governed by the crossover between two critical points: one associated with frictionless isotropic jamming and a second corresponding to frictional shear jamming. Here, we show that orthogonal perturbations to the flows, an effective method for tuning shear thickening, can also be folded into this universal scaling framework. Specifically we show that the effect of adding orthogonal shear perturbations can be incorporated into the scaling variable via a multiplicative function, determined through our measurements, to achieve collapse of the entire thickening and dethickening dataset onto a single universal curve. We then show that this universal scaling framework can be used to control the phase behavior in thickening and jamming suspensions.

Modern experimental methods enable the creation of self-assembly building blocks with tunable interactions, but optimally exploiting this tunability for the self-assembly of desired structures remains an important challenge. Many studies of this inverse problem start with the so-called fully addressable limit, where every particle in a target structure is different. This leads to clear design principles that often result in high assembly yield, but it is not a scalable approach—at some point, one must grapple with “reusing” building blocks, which lowers the degree of addressability and may cause a multitude of off-target structures to form, complicating the design process. Here, we solve a key obstacle preventing robust inverse design in the “semiaddressable regime” by developing a highly efficient algorithm that enumerates all structures that can be formed from a given set of building blocks. By combining this with established partition-function-based yield calculations, we show that it is almost always possible to find economical semiaddressable designs where the entropic gain from reusing building blocks outweighs the presence of off-target structures and even increases the yield of the target. Thus, not only does our enumeration algorithm enable robust and scalable inverse design in the semiaddressable regime, our results demonstrate that it is possible to operate in this regime while maintaining the level of control often associated with full addressability.

Multipartite entanglement is a valuable resource for quantum technologies. However, detecting this resource can be challenging: for genuine multipartite entanglement, the detection may require global measurements that are hard to implement experimentally. Here we introduce the concept of entanglement detection length, defined as the minimum number of particles that have to be jointly measured in order to detect genuine multipartite entanglement. For symmetric states, we show that the entanglement detection length can be determined by testing separability of the marginal states. For general states, we provide an upper bound on the entanglement detection length based on semidefinite programming. We show that the entanglement detection length is generally smaller than the minimum observable length needed to uniquely determine a multipartite state, and we provide examples achieving the maximum gap between these two quantities.

We investigate the role of magic resource in the quantum capacity of channels. We consider the quantum channel of the recently proposed discrete beam splitter with the fixed environmental state. We find that if the fixed environmental state is a stabilizer state, then the quantum capacity is zero. Moreover, we find that the quantum capacity is nonzero for some magic states, and the quantum capacity increases linearly with respect to the number of single-qudit magic states in the environment. We also bound the maximal quantum capacity of the discrete beam splitter in terms of the amount of magic resource in the environmental states. These results suggest that magic resource can increase the quantum capacity of channels; it sheds new insight into the role of stabilizer and magic states in quantum communication.

The chaotic dynamics of quantum many-body systems are expected to quickly randomize any structured initial state, delocalizing it in the Fock space. In this Letter, we study the spreading of an initial product state in Hilbert space under dual-unitary dynamics, captured by the inverse participation ratios and the distribution of overlaps (bit-string probabilities). We consider the self-dual kicked Ising model, a minimal model of many-body quantum chaos that can be seen as either a periodically driven Floquet model or a dual-unitary quantum circuit. Both analytically and numerically, we show that the inverse participation ratios rapidly approach their ergodic values, corresponding to those of Haar random states, and establish the emergence of the Porter-Thomas distribution for the overlap distribution. Importantly, this convergence happens exponentially fast in time, with a timescale that is independent of system size. We inspect the effect of local perturbations that break dual unitarity and show a slowdown of the spreading in Fock space, indicating that dual-unitary circuits are maximally efficient at preparing random states. Our Letter establishes bridges between the dynamics of many-body systems and random matrix theory through the time evolution of structured initial states and finds natural applications in demonstrating a quantum advantage in random sampling and in benchmarking quantum devices.

The interplay between thermodynamics, general relativity, and quantum mechanics has long intrigued researchers. Recently, important advances have been obtained in thermodynamics, mainly regarding its application to the quantum domain through fluctuation theorems. In this Letter, we apply Fermi normal coordinates to report a fully general relativistic detailed quantum fluctuation theorem based on the two point measurement scheme. We demonstrate how the spacetime curvature can produce entropy in a localized quantum system moving in a general spacetime. The example of a quantum harmonic oscillator living in an expanding universe is presented. This result implies that entropy production is strongly observer dependent and deeply connects the arrow of time with the causal structure of the spacetime.

A wide variety of dissipative state preparation schemes suffer from a basic time-entanglement tradeoff: the more entangled the steady state, the slower the relaxation to the steady state. Here, we show how a minimal kind of adaptive dynamics can be used to completely circumvent this tradeoff, and allow the dissipative stabilization of maximally entangled states with a finite timescale. Our approach takes inspiration from simple fermionic stabilization schemes, which surprisingly are immune to entanglement-induced slowdown. We describe schemes for accelerated stabilization of many-body entangled qubit states (including spin squeezed states), both in the form of discretized Floquet circuits, as well as continuous time dissipative dynamics. Our ideas are compatible with a number of experimental platforms.

Observations of massive supermassive black holes (SMBHs) in the early Universe challenge existing black hole formation models. We propose that soliton cores in fuzzy dark matter (FDM) offer a potential solution to this timing problem. Our FDM cosmological zoom-in simulations confirm that, for a particle mass $m_{\mathrm{FDM}}\sim {10}^{-22}\mathrm{eV}$, solitons are well developed at redshift $z\sim 7$ with masses of $\sim {10}^9{M}_{\odot }$, comparable to the observed SMBHs. We then demonstrate using hydrodynamic simulations that, compared to cold dark matter, these high-$z$ massive FDM solitons with mass $M_s$ can provide additional gravitational potential to accrete gas and boost the Bondi accretion rate of a growing black hole seed with mass $M_{\mathrm{BH}}$ by up to 2–4 orders of magnitude, in the regime of efficient cooling and negligible radiation pressure. This accretion boosting mechanism is effective for ${10}^{-22}\lesssim m_{\mathrm{FDM}}\lesssim {10}^{-20}\mathrm{eV}$ and potentially beyond as long as $M_s>M_{\mathrm{BH}}$.

Adiabatic passage in systems of interacting bosons is substantially affected by interactions and interparticle entanglement. We consider stimulated raman-adiabatic-passage-like schemes in Bose-Hubbard chains that exhibit low-dimensional chaos (a three-site chain) and high-dimensional chaos (more than three sites). The dynamics that is generated by a transfer protocol exhibits striking classical and quantum chaos fingerprints that are manifested in the mean-field classical treatment, in the truncated Wigner semiclassical treatment, and in the full many-body quantum simulations.

Quantum simulations of Hubbard models with ultracold atoms rely on the exceptional control of coherent motion provided by optical lattices. Here we demonstrate enhanced tunability using an optical superlattice in a fermionic quantum gas microscope, evidenced by long-lived coherent double-well oscillations, next-nearest-neighbor quantum walks in a staggered configuration, and correlated quantum walks of two particles initiated through a resonant pair-breaking mechanism. We furthermore demonstrate tunable spin couplings through local offsets and engineer a spin ladder with ferromagnetic and antiferromagnetic couplings along the rungs and legs, respectively. Our Letter underscores the high potential of optical superlattices for engineering, simulating, and detecting strongly correlated many-body quantum states, with direct applications ranging from the study of mixed-dimensional systems to fermionic quantum computing.