Papers

We experimentally demonstrate an entanglement-based Quantum-Secure Time Transfer (QSTT) system in an emulated low Earth orbit satellite-to-ground channel using a type-0 Sagnac-based entangled-photon source. Our new QSTT system delivers a finite Quantum Key Distribution (QKD) key rate of approximately $3~$bits$~\text{s}^{-1}$ with a $10^{-10}$ security parameter, providing a $30$-fold increase in the QKD key rate compared to the state-of-the-art entanglement-based QKD system delivered by the Micius satellite. Beyond this high key rate outcome, novel to our QSTT system is a GPS-free clock synchronization, optimized use of QKD, embedded post-quantum security, and obfuscation of the system configuration via use of a pre-shared key. Collectively, these enhancements deliver the most efficient and secure deployment of QSTT to date, and point the way forward to high-accuracy ultra-secure time transfer in space.

Limited qubit connectivity is a central architectural constraint in superconducting quantum processors, whose planar layouts require additional gates to mediate interactions between distant qubits. Here, we use the AshN control scheme, where rich two-qubit control on every nearest-neighbour pair allows a logical interaction and the required qubit routing to be merged into a single native operation, effectively transforming a sparse hardware graph into a more connected computational architecture. For the benchmark instances studied, the resulting synthesis capability enables reliable execution on constrained one- and two-dimensional lattices, with compiled two-qubit gate counts approaching those of an all-to-all-connected reference. Across seven benchmark circuits on one- and two-dimensional topologies, the AshN-based implementation achieves geometric-mean reductions of $45.2\%$ and $43.7\%$ in two-qubit gate count compared with controlled-Z-based compilation, respectively. Using AshN gates, we prepare an eight-qubit two-excitation Dicke state with a fidelity of $0.736$ and certify its genuine multipartite entanglement using a fully positive-partial-transpose witness, whereas the same witness does not certify entanglement for the CZ-based implementation. The state fidelity and entanglement certification remain robust across the tested lattice configurations, including those with up to three connectivity defects. Our work establishes native-gate engineering as a practical approach to mitigating connectivity constraints.

We study modular transformation formulas from the viewpoint of Mellin space. The basic observation is that the functional relation between the Hurwitz zeta function and the polylogarithm can be used to organize modular transformations as reflection identities of Mellin kernels, while the accompanying polynomial anomalies arise from contour deformations. We first illustrate this mechanism for the $q$-$\theta$ function and then extend it to the elliptic Gamma function. In the latter case, independently Mellin transforming the two elliptic directions leads to a trilinear reflection identity relating the three elliptic Gamma functions appearing in the SL$(3,\mathbb{Z})$ modular formula, while the associated contour deformation reproduces the cubic Bernoulli polynomial. Further reflection formulas lead to a weighted $q$-Pochhammer type function with a modular transformation analogous to that of the $q$-$\theta$ function, as well as a transposed trilinear reflection identity analogous to the Mellin space structure underlying the SL$(3,\mathbb{Z})$ transformation. Our results suggest that Mellin space reflection identities provide a useful organizing principle for constructing and studying modular special functions beyond the standard multiple elliptic Gamma hierarchy.

While polarization stability is common in many optical systems, intentional polarization bi-stability is also important for polarization-encoded computing. We propose a mesa orientation strategy to engineer the polarization switching of vertical-cavity surface-emitting lasers (VCSELs). Further experiments demonstrate improved polarization locking performance.

The linear size of a bulk optical astronomical spectrograph scales with the diameter of the primary mirror of the corresponding telescope. As modern telescopes continue to increase in aperture size, miniaturization of the spectrograph becomes crucial beyond the offered advantages in terms of multifunctional integration and photon efficiency. The presented concept of development for a Compact Arrayed Waveguide Stacked Multi-Object Spectrograph (CAWSMOS) includes the design of the Arrayed Waveguide Grating (AWG) chips, the stacking frame and cross-dispersion optics for the imaging of multiple spectral orders per AWG. It aims to reduce the cost and size of astronomical spectrographs while also improving efficiency. This will bring the AWG technology closer to the realization of its full potential for ground based, airborne and spaceborne astronomical applications. Part of this development is an extension of the Potsdam Arrayed Waveguide Spectrograph (PAWS). To do that, the Zemax model is compared to PAWS calibration data, finding that the position can be matched with the measurement within 28 px in x and 18 px in y-direction. It also shows a discrepancy between the measured PSF size and the Zemax model of around factor five, and that the detector area can only partially accommodate a second chip.

In the matrix model of two-flavor adjoint QC$_2$D, we study the low-lying states and their properties in the intermediate-to-strong (Yang-Mills) coupling regime. The model has a classical $SU(2)_R$ chiral symmetry and the eigenstates of the Hamiltonian can be organized in its irreps. We construct the energy eigenstates in presence of a chiral chemical potential $c$ using the variational techniques. We find that when $c=0$, the ground state is always a $SU(2)_R$ singlet, irrespective of the coupling strength $g$. However, as $g$ is tuned from intermediate to strong coupling, the system under goes a crossover from a unique to a doubly degenerate ground state. The degeneracy in the strong coupling regime spontaneously breaks the axial $\mathbb{Z}_8$, while preserving the chiral symmetry. When $c \neq 0$, we find that there can be level crossings which correspond to quantum phase transitions (QPTs). Depending on the ground state, there are three possible phases. The $SU(2)_R$ symmetry is spontaneously broken in only one of these phases, and this phase can only emerge for intermediate $g$ with moderate values of $c$. In the $g-c$ plane this phase corresponds to a narrow window, outside which $SU(2)_R$ is always preserved.

Determining whether a mixed quantum state is uniquely determined among all states by its k-body marginals (k-UDA) is a fundamental problem in quantum system certification. We develop a range-based approach to this problem by analyzing the structure of the range of the global state. For three-qubit states, we show that states with GHZ-SLOCC-free ranges are 2-UDA at ranks one, three, and four. We derive a necessary and sufficient range criterion for rank-two 2-UDA states and reduce it to a finite quadratic-form test. To cover the remaining range configurations, we formulate an exact range-restricted semidefinite programming criterion and extend it to arbitrary finite-dimensional tripartite states. We also show that every three-qubit state of rank at least five is not 2-UDA, and further extend high-rank obstructions to multipartite systems. For a channel-based multipartite family, we characterize exactly when a state is $(n-1)$-UDA and show that lower-order marginals never suffice. Finally, we apply these results to the certification of genuine multipartite entanglement.

Well-understood fractional quantum Hall states in GaAs and graphene can be described in terms of weakly interacting composite fermions. It is natural to expect that the same unifying principle applies to the putative fractional quantum spin Hall effect in MoTe$_2$. Since the quantum spin Hall effect involves two spin components, two types of composite fermions must be present. We classify all two-component composite-fermion states at the filling factor $\nu=3$. The classification includes the three classes of states, which were introduced from different physical perspectives in Refs. Sodemann Villadiego, Phys. Rev. B 110, 045114 (2024), Jian et al., Phys. Rev. X 15, 021063 (2025), and May-Mann et al., Phys. Rev. B 111, L201111, (2025), as well as two new classes of states. A majority of the composite-fermion states break the time-reversal symmetry. We review quasiparticle charges, statistics, and edge theories for each possible state. We also address a way of identifying the experimentally relevant state or states. This can be accomplished by combining three probes. First, the shot noise technique provides information about fractional charges. Second, thermal conductance helps count edge modes. The third probe is based on a new idea and involves transport between two quantum point contacts along a single edge. We find that the current from one contact to the other depends on the shape of the edge channel, which can be controlled with a side gate. The probe reveals the emergent symmetry group of the low-energy edge theory.

We study modulus stabilization by background fluxes. Within the truncated complex-structure sector, the F-term conditions of the complex structure moduli are described by a holomorphic quadratic equation. As concrete examples, we consider the $T^6/(\mathbb{Z}_2\times\mathbb{Z}_2')$ orientifold model and a simple Calabi-Yau compactification. The modulus values show specific patterns. For example, they exhibit a structure related to the Farey sequence. The void structure appears around modulus vacua with high degeneracies. We find a correlation between the degeneracy and the void area. The modulus vacua are related by discrete Abelian symmetries generated by the Gauss composition law, which includes the CP symmetry. Spontaneous CP violation is also discussed.

We study a six-dimensional SU(9) grand unified model with rank-reducing discrete boundary conditions and continuous Wilson line phases on the orbifold $T^2/\mathbb Z_4$. We show that the model can realize grand unification of the Standard Model gauge interactions and electroweak symmetry breaking via the Hosotani mechanism. The model has several attractive features. Two Higgs doublets arise as zero modes of the extra-dimensional components of the gauge field, and the leptons and quarks in each generation are separately embedded into two bulk multiplets, in the ${\bf 36}$ and ${\bf 84}$ representations of SU(9), respectively, without exotic matter. Furthermore, proton decay processes mediated by the gauge bosons in the bulk are absent, because the leptons and quarks belong to different bulk multiplets.

We predict a new type of stable three-dimensional (3D) vortex quantum droplets in binary Bose-Einstein condensate arranged into ring clusters that per-sistently rotate in the external potential. In contrast to clusters composed from localized quantum droplets, the states introduced here represent interacting vortex lines with identical topological charges nested in common 3D envelope and existing in much broader parameter range in comparison with local-ized quantum droplets. The intricate interplay between mean-field nonlinearity of Bose-Einstein condensate, quantum fluctuations described by Lee-Huang-Yang correction, Coriolis force arising due to rotation, and external potential leads to substantial variations of cluster shape upon increase of its rotation frequency. Rotating vortex clusters bifurcate from single-vortex quantum droplets and exist only above critical value of the rotation frequency that decreases with increase of chemical potential and depends on the number of vortex lines in the cluster. The radius of the cluster decreases with increase of rotation frequency and weakly varies with chemical potential, which determines mostly localization of the individual vortices in cluster and overall width of its envelope. Vortex droplet clusters are very robust objects existing in stable form in wide intervals of the number of particles for any number (odd or even) of vortex lines forming them. Our results may open the route to observation of stable arrays of vortex lines of different configurations per-forming regular collective motion in condensate.

The usual WKB analysis for quantum tunneling applies when the tunneling action is large, as it is for tall, wide potential barriers. In contrast we analyze tunneling when the action is small, as it is for tunneling across a tall, thin barrier. We develop a perturbative analysis where the control parameter is the inverse of the area under the potential barrier and apply our technique to several examples in $1+1$ dimensions. In resonant situations for bound particles we find that the tunneling probability grows with time as $\propto t^2$, while in non-resonant situations it grows linearly with time. We evaluate not only the tunneling probability but also the time-dependent tunneling wavefunction for a particle that escapes to infinity, i.e. from a quasi-bound state to the continuum.

We propose a hybrid sharp-diffuse interface representation for modeling intermittent and isolated topological transitions during Cahn-Hilliard phase coarsening. Away from topological events, the evolution is approximated by the Mullins-Sekerka sharp-interface limit system and computed using a boundary integral formulation. When diffuse transition layers overlap, a novel interface surgery algorithm resolves topology changes through a localized Cahn-Hilliard pseudo-time evolution, after which the sharp-interface calculation is resumed. We develop the mathematical formulation underlying this decomposition, present a simple two-dimensional numerical implementation, and simulate a mass-exchange problem with interface coalescence. By localizing the diffuse evolution to topological events, the method achieves a speedup of two to three orders of magnitude over conventional diffuse-interface simulations.

The layer Hall effect has been exclusively attributed to layer-locked Berry curvature, posing a fundamental barrier to its realization in conventional magnets. Here we report a fundamentally distinct layer Hall effect for bosonic excitations, i.e., magnons, which originates solely from non-reciprocal dipolar scattering at heterointerfaces, thereby decoupling the phenomenon from geometric-phase mechanisms. Using a microscopic scattering theory, we demonstrate that a longitudinal temperature gradient drives opposite transverse thermal Hall currents in a nanowire atop a magnetic film, with the direction fully reconfigurable by the applied magnetic field. The effect yields a significant Hall angle of $\sim 6^{\circ}$ in conventional magnetic heterostructures, eliminating the need for topological engineering. Our findings establish a scattering-driven paradigm for layer Hall effect, extendable to ferrons and polar phonons, and predict a Hall response that is readily detectable in conventional magnetic heterostructures.

Gaucher disease (GD), the most common lysosomal storage disorder, alters red blood cell (RBC) mechanics and circulation, contributing to vascular occlusions, bone infarcts, and splenomegaly. However, the individual roles of GD-RBC biophysical properties in these processes remain unclear. Here, we present a combined computational-experimental investigation to quantitatively characterize GD-RBC biophysical properties and determine how specific mechanical parameters drive abnormal RBC behavior. Informed by experimental data, we independently quantify key RBC properties, including shear modulus (mu), surface-to-volume ratio (S/V), and bending modulus (k_c). Based on these parameters, we construct three GD-RBC subtypes (GD-RBC1-3) to systematically isolate their individual contributions. At the single-cell level, optical tweezers simulations show up to ~27% reduction in axial diameter and ~42% reduction in transverse compression. Tank-treading dynamics exhibit non-monotonic behavior, with rotation frequencies increasing by up to ~70% or decreasing under elevated bending rigidity. In confined flow, traversal times through microchannel constrictions increase by more than a factor of two, while splenic slit passage times rise from ~250 ms (control) to >1200 ms for the severe GD-RBC subtype, approaching a functional no-passage threshold. At the population level, viscosity simulations demonstrate that these alterations collectively elevate blood viscosity, with small fractions (~4.0%) of highly rigid cells disproportionately increasing flow resistance. Overall, this study provides a quantitative and mechanistic framework that disentangles the contributions of key RBC parameters to abnormal behavior in GD, linking cellular-scale biophysics to hematologic dysfunction and microvascular occlusion.

Fractional Chern insulators have attracted broad interest as lattice analogs of fractional quantum Hall states without Landau levels. However, low-filling fractional Chern insulators are fragile because charge-ordered phases can compete strongly with the fractional topological liquid. Here, we propose a center-decorated kagome model, motivated by geometry-tunable artificial lattices, in which the center-site hopping $t_2$ provides a direct knob for the quantum geometry of an isolated $C=1$ flat band. Here quantum geometry refers to the Berry curvature and Fubini–Study metric, which determine the form factors of interactions projected into the Chern band. Exact diagonalization shows that tuning $t_2$ away from the flatness-optimized kagome limit reduces the trace-condition deviation, suppresses competing charge order, and enhances the many-body stability at both $\nu=1/3$ and the more fragile $\nu=1/5$ filling. At $\nu=1/5$, this stability-enhanced window persists under nearby interaction profiles, including variations of the dominant third-neighbor repulsion and weak nearest-neighbor admixtures. Low-energy spectra, spectral flow, quasihole and entanglement counting, static structure factors, and the quantized total many-body Chern number $C_{\mathrm{tot}}=1$ consistently support Laughlin-like fractional Chern insulators. These results identify quantum-geometry engineering as a route to stabilizing dilute fractional Chern insulators beyond band-flatness optimization alone.

Accurate electron-ion collision models are central to predicting transport in fusion and space plasmas, yet most practical formulations rely on binary-collision assumptions and impact-parameter cutoffs whose quantitative accuracy is difficult to assess directly. We develop a first-principles simulation framework for collisional transport by solving the Newton-Lorentz equations for test electrons in the many-body electric field of a Debye-screened ion background, without imposing binary-collision closures or artificial lower cutoffs. The method combines explicit force summation within a Debye sphere, a volume-preserving particle pusher, and adaptive time stepping, enabling stable and scalable simulations in both unmagnetized and magnetized plasmas. Using simulation-based measures of momentum relaxation and cross-field diffusion, we recover the classical scalings for the electron-ion collision frequency and perpendicular diffusion coefficient, namely $\nu_{ei} \propto v_{th}^{-3}$ and $D_\perp \propto B^{-2}$. Within the parameter range studied, both simulated coefficients are lower than their corresponding classical estimates by approximately 15-25%. These regime-specific benchmark results indicate that classical transport theory captures the leading scaling behavior, but that the corresponding quantitative prefactors can remain sensitive to many-body and near-field effects in the simulated regime. The framework therefore provides a computational benchmark for testing and improving reduced collision operators and transport models.

Microlensing surveys typically apply automated criteria to exclude lightcurves that depart from time-symmetric and achromatic Paczyński curves. In surveys using such automated detection pipelines, occultation of microlensed images by circum-lens material could lead to underdetection or misclassification of ring- or disk-bearing compact object populations. This work characterizes the family of lightcurve morphologies by which uniform thin circum-lens disks of varying size and orientation, and low mass relative to their host lens, can intersect the ray paths produced during microlensing events. These morphology classes are paired with squared residuals relative to an unocculted lightcurve. We find that substantial deviations from an unocculted microlensing curve can occur across a wide range of parameter space. This effect holds relevance for free-floating planets and brown dwarfs where disks or ring systems can be present. Another potential consideration is that disk-shaped accretion flows onto primordial black holes (PBHs) during the cosmic dark ages could have resulted in remnant quiescent disks of baryonic material. Pipelines should be designed to account for disk-bearing lens populations, opening previously underutilized avenues to potentially observe disks and rings in these contexts and ensuring populations are accurately characterized.

BosonSampling is among the most prominent candidates for demonstrating quantum advantage. However, while the hardness of BosonSampling relies on photon-number-resolving detection, many experimentally relevant settings and applications instead use binary readout based on threshold or parity measurements, whose computational complexity has not yet been rigorously characterized. In this work, we investigate the computational complexity of BosonSampling with threshold and parity measurements in the linear-mode regime, where the number of modes scales linearly with the number of photons and is most relevant to current experiments. In particular, we establish average-case #P-hardness of estimating typical output probabilities in threshold and parity BosonSampling, a crucial ingredient in proving the classical hardness of the corresponding sampling problems. The resulting imprecision bounds match those obtained in prior hardness results for standard photon-number-resolving BosonSampling in the linear-mode regime. The key technical ingredient is a Fourier-coefficient extraction method, induced by coherent beam-splitter rotations, that extracts hidden hard components within coarse-grained output probabilities. These results indicate that the hard output-probability structure of photon-number-resolving BosonSampling can persist under natural binary coarse-grainings, even in collision-dominant regimes.

We develop a low-energy theory of interface states in anisotropic multivalley Dirac systems whose masses and kinetic parameters are allowed to vary across an interface. For sharp interfaces, current-conserving matching conditions yield analytic expressions for the existence, localization and dispersion of the bound states. We show that the interface velocity is determined by the weighted tangential kinetic terms on the two sides of the seam. Their cancellation can suppress the linear velocity and generate an interface band that is flat to leading order near the projected Dirac point. For the special antisymmetric configuration in which both the Dirac mass and the tangential kinetic coefficient reverse sign with unchanged magnitude, the transparent sharp-interface solution is exactly dispersionless for all conserved momenta within the linear Dirac theory, while the surrounding bulk bands remain dispersive. We extend the theory to smooth interfaces, where the modified bound-state envelope changes the linear interface velocity through a spatial average of the tangential kinetic coefficient. We also investigate quadratic corrections in the kinetic \(\sigma_x\) and \(\sigma_y\) channels. To first order in their coefficients and through linear order in the interface momentum, these terms shift the interface-state energy but produce no additional correction to the linear velocity. Finally, we combine continuum and lattice models to show how interface modes from distinct valleys hybridize and how the resulting dispersions depend on microscopic interface properties. Our results establish design principles for controlling the dispersion, localization, and hybridization of Dirac interface states. We further examine two graphene-based mass-domain-wall models as experimentally inspired examples of dispersive copropagating and counterpropagating interface states.

We investigate gravitational-wave birefringence from pulsar glitches in dynamical Chern-Simons gravity, a parity-violating extension of general relativity motivated by string theory and quantum gravity. Using the Hartle-Thorne slow-rotation formalism to model the neutron star background and a perturbative treatment of the Chern-Simons coupling $\alpha$, we derive the modified Regge-Wheeler equation governing axial gravitational perturbations and compute the resulting polarization-dependent phase shift. The parity-violating interaction produces a fractional asymmetry between the right- and left-handed circular polarizations that scales as $\alpha^2$, grows linearly with frequency and rotation rate, and falls as the fourth power of the stellar radius. For a constant-density interior model we obtain an analytic matching solution for the background scalar field, and show that the interior curvature factor vanishes identically–the interior solution being conformally flat–so that the scalar dipole is sourced entirely in the vacuum exterior; a centrally condensed equation of state can only increase the predicted signal. We further extend the analysis to a two-fluid model incorporating differential rotation between the neutron superfluid and the charged component; the resulting correction is bounded by the fractional glitch amplitude itself, independently of the equation of state, and is negligible for typical pulsar parameters. Expressed through the dimensionless quantity $\zeta \propto \alpha M/R_\star^{3}$, the fractional polarization asymmetry for millisecond pulsars reaches $\sim 10^{-3}$ at kilohertz frequencies at the boundary of perturbative validity–four orders of magnitude above the sensitivity of current ground-based detectors to strain asymmetries. However, realistic bounds are limited by the signal-to-noise ratio required to resolve a ratio of gravitational wave strains.

In this work, we study quantum CSS codes with transversal $T$ gates. Here, $T$ gate transversality is meant in the strongest sense; the application of physical $T$ to every physical qubit yields logical $T$ on every logical qubit, without Clifford corrections. Despite the importance of the $T$ gate in fault-tolerant quantum computation, the parameters of asymptotic families of such codes have not been improved since the work of Hastings and Haah in 2017, and Haah in 2018. In this work, we significantly broaden the achievable parameters of quantum code families with transversal $T$ gates, both expanding the regime of achievable polynomial rate and distance, and constructing such codes with constant rate and growing distance; this is the first time the latter has been achieved, even when allowing Clifford corrections after the transversal $T$ gate. These are also the first codes achieving $\gamma \to 0$ for a code with a transversal $T$ gate, where $\gamma$ is the overhead exponent of magic state distillation. To do this, we develop a framework of divisible decreasing monomial codes, punctured at a downward-closed set on the Boolean hypercube to create logical qubits. We prove a closed-form expression for the distance of such a code punctured at such a set, which may be of independent interest. We first instantiate this with an explicit construction based on weighted Reed-Muller codes, puncturing at low Hamming-weight points, and then with a randomised construction, where a small random set of points is protected from the puncturing to save quantum code distance, achieving improved parameters.

A self-contained hydrodynamic theory is proposed to reconcile the discrepancy between divergent Stokesian velocity fluctuations and finite experimental measurements in sedimenting suspensions. We show that the compensating backflow induces non-negligible inertia, giving rise to an emergent screening length $\xi \sim a\phi^{-1/3}Re_p^{-1/3}$ far exceeding the mean interparticle spacing $a\phi^{-1/3}$ even at vanishingly small particle Reynolds numbers. This backflow inertial screening, together with finite-time viscous diffusion, arrests the indefinite spatiotemporal growth of large-scale velocity fluctuations. The resulting velocity fluctuations scale as $\delta u \sim \phi^{1/3}V_sRe_p^{-1/6}$, together with the viscous correlation time $\tau_c=\xi^2/\nu$, reproducing the well-known hydrodynamic self-diffusivity scaling $D_H\sim V_s a$. The theory predicts the prefactors of these scaling laws without adjustable parameters, in good quantitative agreement with experimental measurements. It also successfully captures the experimentally observed crossover from the finite-correlation regime to the finite-system regime as the screening length becomes comparable to the system size.

In oscillator networks sustained by finite resources, synchronization can depend on both the total resource and its spatial distribution. We study a duplex system whose activity layer consists of chaotic Hindmarsh–Rose oscillators and whose transport layer redistributes a conserved resource through a degree-biased Markov process. The stationary resource field is characterized analytically, and its existence, uniqueness, and convergence are established. By embedding this field into a local adaptive feedback law, the available resource is converted into node-dependent dissipation, for which Lyapunov analysis guarantees convergence to the synchronization manifold. Numerical results show that topology bias reorganizes the transient route to synchronization. Weak bias produces an almost collective contraction, whereas intermediate bias creates a hub-initiated recruitment hierarchy that extends toward middle-degree and peripheral nodes. Under stronger bias, the degree hierarchy becomes more pronounced while peripheral recruitment slows because adaptive dissipation is concentrated on structurally privileged nodes. Across the explored parameter range, this localization–coverage tradeoff is accompanied by a non-monotonic synchronization response at fixed total resource. The largest Lyapunov exponent remains positive after synchronization and the correlation dimension changes only modestly, consistent with suppression of transverse deviations while chaotic motion is retained on the synchronization manifold.

The critical exponents and universality classes of localization transitions in quasiperiodic systems are of fundamental importance for understanding critical phenomena in aperiodic systems. Here we show that the dynamical critical behavior can be tuned without adding new terms or changing the form of the Hamiltonian, but solely by varying the incommensurate frequency of the quasiperiodic onsite potential. We construct a family of incommensurate frequencies from the limiting ratios of generalized Fibonacci sequences controlled by the parameters $(m,n)$, and use them to define the quasiperiodic onsite potential. By combining generalized fidelity susceptibility, localization-length scaling, and finite-size gap analysis, we find that the correlation-length exponent is insensitive to the choice of the incommensurate frequency and remains consistent with the correlation-length critical exponent, $\nu \simeq 1$, in the localization transition of the standard Aubry–Andr'e–Harper model. In contrast, the dynamical exponent extracted from the low-energy gap scaling varies systematically with the incommensurate frequency. Our results show that changing the incommensurate frequency provides a simple way to tune dynamical critical scaling in deterministic aperiodic systems. Our results suggest instead that the arithmetic structure of an irrational number can serve as a control parameter for nonequilibrium quantum dynamics, enabling the tuning of dynamical critical behavior without changing the microscopic Hamiltonian or the physical spatial dimension.

A new approach to tokamak magnetic control enabling high-precision plasma shaping and novel real-time adaptability is experimentally demonstrated on the Tokamak a Configuration Variable (TCV). The method is motivated by the insight that, under appropriate assumptions, a real-time inverse Grad-Shafranov solver approximates an optimal control policy for plasma boundary regulation. Building on this, a control architecture is developed in which classical controllers enforce operational constraints while a fast surrogate model provides a real-time inverse mapping from the desired plasma boundary to Poloidal Field Coil currents. Experimental results on TCV demonstrate improved plasma shaping with respect to the standard discharge preparation procedure — albeit without explicit real-time shape feedback — while enabling flexible response to asynchronous events. It is shown that a single network provides satisfactory performance across a range of plasma magnetic configurations. Real-time adaptivity is demonstrated in simulation, and partially in experiment, through adaptive strike point motion and early termination in response to a real-time trigger. These results suggest a viable path toward magnetic control architectures that reduce reliance on dense diagnostic coverage while maintaining high-accuracy plasma shaping, with potential relevance for future fusion power plant operation.

We study eight-point amplitudes in the planar $\mathcal{N}=4$ Super Yang-Mills theory in multi-Regge kinematics in the Mandelstam region that receives contributions from both two- and three-Reggeon exchange. We use an effective field theory approach to compute the leading contribution from three-Reggeon exchange, and we explicitly evaluate the relevant diagrams up to four loops. We also propose a compact Fourier-Mellin representation for the contribution from two-Reggeon exchange in this region which involves the same ingredients as in other Mandelstam regions and can in principle be evaluated to any desired order in perturbation theory. To validate our proposal, we show that we can reproduce the multi-Regge limit of the known results for octagons up to three loops. We then combine the contributions from two- and three-Reggeon exchange to obtain novel results for octagons in MRK up to next-to-leading-logarithmic accuracy at four loops for the maximally helicity violating (MHV) configuration, and up to three loops for non-MHV contributions. We also discuss how our result can be extended to more particles, and we present the contribution from three-Reggeon exchange for three-loop MHV amplitudes with an arbitrary number of legs.

Spatial patterns, such as those in dryland vegetation models, have historically been studied in systems of reaction-diffusion systems with pattern onset via a Turing bifurcation from a spatially uniform state. More recently, spatial patterns have been considered in models that incorporate spatially extended interactions via nonlocal interaction kernels. It remains largely underexplored if and how the choice of nonlocal interaction kernel contributes to differences in pattern formation and persistence, particularly in models that contain competition and facilitation. Here, we investigate spatial patterns in a reaction-diffusion model for a single species that includes nonlocal competition and facilitation processes; Gaussian, exponential, algebraic, hat, and smooth hat kernels are considered as specific examples. Via a center manifold analysis, and using the relative spatial scale of competition to facilitation and the death rate as bifurcation parameters, we identify that the choice of kernel has impacts on the pattern forming bifurcation. Bifurcations using the Gaussian, exponential, and algebraic kernels largely follow expectations of Turing patterns, but patterns in the hat and smooth hat kernels can form even when the scale of competition is less than that of facilitation. The dynamics of patterns far from onset are investigated via numerical continuation methods. The model produces the so-called "Turing-before-Tipping" phenomenon demonstrating that the arrangement into spatial patterns is an effective resilience mechanism against harsh conditions. Again, there is a kernel-dependent dichotomy in pattern behavior. Early warning signs for population extinction are observed with the Gaussian, exponential, and algebraic kernels, but not under the hat or smooth hat cases.

Scalar-induced gravitational waves (SIGWs) provide a direct probe of the enhanced primordial curvature perturbations that may also produce primordial black holes (PBHs). We forecast the capability of the space-based gravitational-wave observatory Taiji to search for an SIGW background generated by a broken-power-law curvature spectrum. A signal-injection study is used to validate the analysis pipeline, after which a pure-noise realization is employed to derive projected upper limits on the curvature-spectrum parameters. We translate these limits into constraints on the PBH abundance using the nonlinear compaction function, critical collapse, and the joint Gaussian distribution of the compaction amplitude and curvature at its peak. The resulting projected $95\%$ upper limits on the PBH dark-matter fraction satisfy $f_{\mathrm{PBH}}^{95\%}<1$ over PBH masses from approximately $6.2\times10^{-18}\,M_\odot$ to $1.7\times10^{-8}\,M_\odot$. We compare the forecast with representative Hawking-evaporation and microlensing bounds. In part of the asteroid-mass interval, the projected Taiji limit is more restrictive than the current Subaru Hyper Suprime-Cam (HSC) microlensing constraint.

We propose a realization of tunable long-range mediated interactions generated by Nambu-Goldstone (NG) modes near spontaneous symmetry breaking. An effective exchange interaction emerges between two distinguishable impurities proportional to the retarded susceptibility mediated by the bath particles. The interaction is mediated by emergent NG modes associated with symmetry breaking in systems, namely the magnon mode in a repulsive two-component Fermi or Bose gas, or the goldstino mode in a Bose-Fermi mixture. When the NG mode is gapped by explicit symmetry breaking, the interaction has a Yukawa-type short-ranged interaction, whereas the gapless limit gives a Coulomb law. Above the NG mode threshold, the Dzyaloshinskii-Moriya-like cross product coupling emerges in a long-range form. Our proposal paves a way towards the realization of a quantum simulator of spin models and polarons with controllable non-local interactions.