We consider quantum light-matter interfaces comprised of multiple layers of two-dimensional tweezer atomic arrays, wherein the lattice spacings exceed the wavelength of light. While the coupling of light to a single layer of such a “superwavelength” lattice is considerably reduced due to scattering losses to high diffraction orders, we show that the addition of layers can suppress these losses through destructive interference between the layers. Mapping the problem to a 1D model of a quantum interface wherein the coupling efficiency is characterized by a reflectivity, we analyze the latter by developing a geometrical optics formulation, accounting for realistic finite-size arrays. We find that optimized efficiency favors small diffraction-order angles and small interlayer separations, and that the coupling inefficiency for two layers universally scales as $N^{-1}$ with the atom number per layer $N$. We validate our predictions using direct numerical calculations of the scattering reflectivity and the performance of a quantum memory protocol, demonstrating high atom-photon coupling efficiency. This opens the way for various applications in tweezer atomic-array platforms.

In disordered Hermitian systems, localization of energy eigenstates prohibits wave propagation. In non-Hermitian systems, however, wave propagation is possible even when the eigenstates of a Hamiltonian are exponentially localized by disorders. We find in this regime that non-Hermitian wave propagation exhibits novel universal scaling behaviors without Hermitian counterpart. Furthermore, our theory demonstrates how the tail of imaginary-part density of states dictates wave propagation in the long-time limit. Specifically, for the three typical classes, namely the Gaussian, the uniform, and the linear imaginary-part density of states, we obtain logarithmically suppressed sub-ballistic transport, and two types of subdiffusion with exponents that depend only on spatial dimensions, respectively. Our work highlights the fundamental differences between Hermitian and non-Hermitian Anderson localization, and uncovers unique universality in non-Hermitian wave propagation.

The moiré superlattice has attracted growing interest in the electromagnetic and optical communities. Here, we extend this concept to time-varying photonic systems by superposing two binary modulations on the refractive index with different modulation periods, i.e., the moiré photonic time crystal (PTC). Such a moiré PTC leads to extremely narrow bands in momentum space that support temporal localized modes, exhibiting periodically self-reconstructing pulses in the time domain. We investigate the tunability of the band structure of the moiré PTC and the temporal localization behavior, which can be greatly manipulated by varying the temporal modulation parameters. Moreover, we explore the Floquet mode-locking mechanism in the moiré PTC, which points toward potential applications in mode-locked lasers with a tunable time width of the generated pulses. The modulation-induced extremely narrow band also offers intriguing opportunities in exceptional-point-enhanced sensing. Our Letter brings the concept of moiré patterns to the field of PTCs, and unveils new possibilities in wave manipulations with time-varying systems.

Recent advancements in indirect-drive inertial confinement fusion (ICF) experiments at the National Ignition Facility (NIF) have achieved a significant milestone by demonstrating target gains greater than one, yet future applications necessitate much higher target gains. One approach to achieving improved implosion performance is to pursue increased fuel compression via a lowered implosion adiabat. Experiments have been performed testing a reduced adiabat by introducing small changes to the drive laser pulse shape and the resulting shock timing for an existing implosion design at 1.9 MJ laser drive with near-ignition performance (experiment N210808). Experiments using the updated design demonstrate, for the very first time, increased compression and fusion yield in ICF implosions on the NIF by using a lower fuel adiabat, and increased compression with a reduced adiabat in high-density carbon ablators. Compared to the previously best-performing experiment with a laser energy of 1.9 MJ, these experiments exhibit increases of up to 80% and 14% in nuclear fusion yield and fuel compression, respectively, and with repeatable performance. Further, it is the only implosion design to have achieved a target gain exceeding one with a laser energy of less than 2 MJ. These findings highlight the efficacy of reduced adiabat designs in achieving higher compression and fusion yields, offering a promising pathway for future ICF applications. This Letter not only addresses a long-standing question in ICF but also paves the way for achieving higher target gains with optimized implosion strategies.

Qubits are the fundamental units in quantum computing, quantum communication, and sensing. In current platforms, such as cold atoms, superconducting circuits, point defects, and semiconductor quantum dots, each qubit requires individual preparation, making identical replication a challenging task. Constructing and maintaining stable, scalable qubits remains a formidable challenge. The race to identify the best one remains inconclusive. Our Letter introduces twisted bilayer materials as a promising platform for qubits due to their tunability, natural patterns, and extensive materials library. Our large-scale first-principles calculations reveal that the moiré superlattices have identical and localized states, akin to the discrete energy levels of an alkali atom. Existing experimental techniques allow for individual initialization, manipulation, and readout. The vast array of 2D materials provides a multitude of potential candidates for qubit exploration. Because of their inherent scalability and uniformity, our proposed qubits present significant advantages over conventional solid-state qubit systems.

We analyze the phase transition between a symmetric metallic parent state and itinerant altermagnetic order. The underlying mechanism we reveal in our microscopic model of electrons on a Lieb lattice does not involve orbital ordering, but derives from sublattice interference.

The bulk-edge correspondence plays a crucial role in topological physics bridging the gap between the bulk topology and the topological edge states, which recently was extended to topological metamaterials having a large number of topological boundary states. In this work, we experimentally observe the $k$-dependent bulk-edge correspondence in the framework of a manmade sonic semimetal, supporting the coexistence of multiple topological phases which are separated by boundaries formed by versatile types of Dirac points. The structure is composed of stacked one-dimensional (1D) extended Su-Schrieffer-Heeger chains through long-range couplings, in which the topological phases are characterized by $k$-dependent winding numbers. Through an elaborately designed methodology for measuring the acoustic pressure amplitude and phase, we not only derive $k$-dependent topological winding numbers but also clearly observe the spatial distribution characteristics of edge states across different phases. Our findings significantly broaden the understanding of these critical topological phases and open up avenues for the manipulation of classical waves.

Beyond conservative systems, altering the wave propagation frequency emerges as a crucial factor across diverse physical domains. This Letter presents a demonstration of bidirectional asymmetric frequency conversion—either upward or downward—depending on the excitation direction, surpassing conventional unidirectional mechanisms. We numerically and experimentally demonstrate its practical realization in a model system of cylindrical granular crystals with intrinsic local resonance coupling. This novel wave transport mechanism arises from the interplay of nonlinear contact, spatial asymmetry, and coupled local resonance. In particular, we show that local resonance coupling induces wavenumber-dependent wave dynamics, including frequency conversion. Given that this local resonance exemplifies avoided crossings (i.e., strong coupling), this Letter may inspire studies on nonlinear systems supporting material or structural resonance.

We propose fractional anomalous Hall crystals (FAHCs) as possible ground states of strongly interacting electrons in parent bands with Berry curvature. FAHCs are exotic states of matter that spontaneously break continuous translation symmetry to form a fractional Chern insulator. We construct a unified family of variational wave functions that describe FAHCs and their competing states in the presence of uniform parent Berry curvature. We calculate their variational energy with Coulomb interactions semianalytically in the thermodynamic limit. Our analysis reveals that FAHCs can be energetically favorable over both Wigner crystals and integer anomalous Hall crystals for sufficiently strong interactions or flat dispersion.

Altermagnetism, an emergent collinear magnetic phase with zero net magnetization and momentum-dependent spin splitting, promises to revolutionize spintronics by leveraging symmetry-driven effects without requiring spin-orbit coupling. Despite its potential, a comprehensive understanding of design principles and spin-splitting mechanisms remains elusive. Here, from a mathematical perspective, we exploit the intrinsic fourfold symmetry and structural versatility of 2D square tessellations to engineer altermagnetic states. By systematically screening the altermagnetic state in all 34 2D square tessellations in the Reticular Chemistry Structure Resource database, we identify the “Lieb” (a regular lattice with 4.4.4.4 tessellation), “fes” (a semiregular net with 4.8.8 tessellation), and “tts” (a semiregular net with 3.3.4.3.4 tessellation) nets as key candidates. A tight-binding Hamiltonian analysis reveals the physical origin of spin splitting across these different tessellated nets. As proof of concept, we demonstrate the pyracylene-based metal-organic framework monolayer $t\text{−}{\mathrm{Cr}}_2[\mathrm{Pyc}\text{−}{\mathrm{O}}_8]$, with the tts net, as a robust altermagnet exhibiting a symmetry-compliant ground state. Our Letter provides a symmetry-driven design framework that bridges the mathematical architecture of tessellations with computational materials discovery, enabling reasonable control of altermagnetism in 2D materials.

We develop a microscopic theory for nonlinear optical response of moiré exciton polaritons in bilayers of transition metal dichalcogenides (TMDs). Our theory allows us to study the tunnel-coupled intralayer and interlayer excitonic modes for a wide range of twist angles ($\theta$), external electric field, and light-matter coupling, providing insights into the hybridization regime inaccessible before. Specifically, we account for the umklapp scattering processes of two exciton polaritons responsible for enhanced nonlinearity, and show that it is crucial for describing interactions at strong hybridization. We reveal a regime of attractive nonlinearity for moiré polaritons, stemming from the anisotropic Coulomb interactions, which can explain some of experimental features of optical response in TMD bilayers. Furthermore, within our theory we demonstrate that the attractive nonlinearity can be tuned into repulsive by applying an external electric field. Our findings show that nonlinear moiré polaritons offer a controllable platform nonlinear polaritonic devices.

Mutual information between particle positions before and after mixing provides a universal assumption-free measure of mixing efficiency at low Reynolds number that accounts for the kinematic reversibility of the Stokes equation. For a generic planar shear flow with time-dependent shear rate, we derive a compact expression for the mutual information as a nonlinear functional of the shearing protocol and solve the associated extremization problem exactly to determine the optimal control under both linear and nonlinear constraints, specifically total shear and total dissipation per unit volume. Remarkably, optimal protocols turn out to be universal and time-reversal symmetric in both cases. Our results establish a minimum energetic cost of erasing information in a broad class of nonequilibrium drift-diffusive systems.

Microphase separation is common in active biological systems as exemplified by the separation of RNA- and DNA-rich phases in the cell nucleus driven by the transcriptional activity of polymerase enzymes acting similarly to amphiphiles in a microemulsion. Here we propose an analytically tractable model of an active microemulsion to investigate how the activity affects its structure and relaxation dynamics. Continuum theory derived from a lattice model exhibits two distinct regimes of the relaxation dynamics and is linked to the broken detailed balance due to intermittent activity of the amphiphiles.

Strong excitation of nuclear resonances, particularly of Mössbauer nuclei, has been a longstanding goal and the advance of novel x-ray sources is promising new options in this regard. Here, we map out the necessary experimental conditions for the more general goal of entering the nonlinear optics regime with nuclei and compare with available technology. In particular, we present a comprehensive theory of nonlinear nuclear excitation in thin-film x-ray cavities by focused x-ray pulses. We thereby identify cavity geometries with broad resonances that allow one to boost the nuclear excitation even at moderately tight focusing and offer the possibility to mitigate radiation damage.

We study one-dimensional lattice anyons with extended Hubbard interactions at unit filling using bosonization and numerical simulations. The behavior can be continuously tuned from bosonic to fermionic statistics by adjusting the topological exchange angle $\theta$, which leads to a competition of different instabilities. We present the bosonization theory in the presence of dynamic gauge fields, which predicts a phase diagram of four different gapped phases with distinct dominant correlations. Advanced numerical simulations determine and analyze the exact phase transitions between Mott insulator, charge density wave, dimerized state, and Haldane insulator, all of which meet at a multicritical line in the parameter space of anyonic angle $\theta$, on-site interaction $U$, and nearest neighbor repulsion $V$. Superfluid and pair-superfluid phases are stable in a region of small $V$.

We study the rapidity distribution in the Lieb–Liniger model and derive exact relations for its derivatives at the Fermi level. The latter enables us to treat analytically the free energy of the system at low temperatures and arbitrary interactions. We calculated the leading-order correction to the well-known result obtained using conformal field theory. In contrast to the leading-order term controlled by the sound velocity or the Luttinger liquid parameter, the new term is controlled by an additional dimensionless parameter. We calculated its series expansions in the limiting cases of weak and strong interactions. Our results are generalized to other Galilean-invariant integrable systems.

We study a mobile impurity in a one-dimensional harmonically confined optical lattice interacting repulsively with a bosonic bath. The behavior of the impurity across baths with superfluid and Mott-insulator domains is examined, including its full back-action effect on the bath. We characterize the bath-impurity phase diagram and reveal the appearance of a correlated counterflow phase, which we support with an analytical model for a mobile impurity-hole pair. This phase shows an extended combined insulator domain of unity filling but no independent domain of constant density. The transition to this phase features a sudden orthogonality and the change of the shape of the impurity’s profile to that of a free particle in an infinite square well. The findings of this work suggest the appearance of unconventional counterflow in trapped imbalanced atomic mixtures.