Abstract Fast quasi-adiabatic driving (FAQUAD) is a central technique in shortcuts to adiabaticity (STA), enabling accelerated adiabatic evolution by optimizing the rate of change of a single control parameter. However, many realistic systems are governed by multiple coupled parameters, where the adiabatic condition depends not only on the local rate of change but also on the path through parameter space. Here, we employ an enhanced FAQUAD framework that incorporates path optimization in addition to conventional velocity optimization, extending it to two-dimensional parameter spaces supporting band gaps, where rapid parameter variations inevitably trigger nonadiabatic transitions. To demonstrate the true power of STA in restoring adiabaticity against these transitions, we use a coupled elastic-waveguide system, where the synthetic parameters–detuning and coupling–are controlled by the thicknesses of the waveguides and connecting bridges. Using scanning laser Doppler vibrometry, we directly map the flexural-wave field and observe the restored adiabatic energy transfer along the optimized path throughout the process. This elastic-wave platform provides a versatile classical analogue for exploring multidimensional adiabatic control, demonstrating efficient and compact implementation of shortcut-to-adiabaticity protocols.

Abstract Real-time scattering dynamics in gauge theories are central to high-energy nuclear physics, but they are notoriously hard to access from first principles. In particular, it remains unclear how a simple propagating probe becomes modified and quantum-mechanically mixed with a dense, dynamical target during a collision. In analogy to high-energy nuclear scattering experiments, we study a real-time scattering process between a propagating state and a dense target in 1 + 1-d massive QED. In our setup, we identify three distinct regimes that qualitatively characterize the evolution: for a dilute medium, the incoming probe state evolves nearly ballistically; in an intermediate setting, it traverses the matter, locally exciting it; and for dense targets, one approaches a black-disk limit, where the matter acts as a strong wall potential. Here we show evidence that the probe’s energy loss rate scales linearly with the path length in the medium, and we study how the entanglement entropy reveals the mixing between the probe and medium states. With the goal of one day replicating high-energy nuclear experiments in quantum devices, we briefly discuss how the current tensor network-based simulations can be translated to a quantum simulator.

The missing first Shapiro step in microwave-irradiated Josephson junctions has been widely interpreted as a hallmark of Majorana bound states. However, conventional mechanisms like junction underdamping or Joule heating can produce similar signatures. Here, we demonstrate that the intrinsic non-linear current-voltage characteristic of low-to-moderate transparency junctions can also suppress the first step, accompanied by distinctive zigzag boundaries between the zeroth and first step at intermediate driving frequencies. Microwave measurements on Al/WTe2 junctions and numerical simulations of a non-linear resistively and capacitively shunted junction model reveal the first-step collapse induced by switching jumps of current, together with zigzag features absent in scenarios solely driven by finite $$\beta$$ or Joule heating. This zigzag signature, therefore, provides a crucial diagnostic tool, emphasizing the necessity of comprehensive analysis of microwave spectra before attributing the absence of the first Shapiro step to Majorana physics. The absence of odd Shapiro steps in microwave-irradiated Josephson junctions (JJs) is considered to be a possible indicator of 4π-periodic supercurrents that are induced by Majorana bound states. Here, by conducting measurements on Al/WTe2 JJs, the authors suggest that the missing first Shapiro step can instead arise from the intrinsic non-linearity of the current–voltage characteristics in low-to-moderate transparency junctions.

Magnetic singularities known as Bloch points (BPs) present a fundamental challenge for micromagnetic theory, which is based on the assumption of a fixed magnetization vector length. Due to the divergence of the effective field at a BP, classical micromagnetics fails to adequately describe BP dynamics. To address this issue, we propose a regularized micromagnetic model in which the magnetization vector can vary in length but not exceed a threshold value. More specifically, the magnetization is treated as an order parameter constrained toan -sphere. This constraint respects fundamental properties of local spin expectation values in quantum systems. We derive the corresponding regularized Landau-Lifshitz-Gilbert equation and the analog of the Thiele equation describing the steady motion of spin textures under various external stimuli. We demonstrate the applicability of our theory by modeling the dynamics of several magnetic textures containing BPs, including domain walls in nanowires, chiral bobbers, and magnetic dipolar strings. The presented results extend micromagnetic theory by incorporating a regularized description of BP dynamics.

Vacuum manifests itself as a nonlinear polarization medium for photons in the presence of strong fields. This hallmark prediction of quantum electrodynamics remains experimentally elusive due to the weak amplitude of light-light interaction in vacuum and the difficulty of distinguishing signals from backgrounds. Here, we propose a scheme for detecting vacuum polarization effects by colliding an ultra-intense vortex laser with an X-ray free-electron laser. We uncover a super light-by-light scattering mechanism, wherein the localized azimuthal phase of the vortex laser imparts substantial tangential momentum to scattered photons. This phase-gradient-induced momentum transfer exceeds the transverse momentum of laser-photons, allowing signal photons to be kinematically deflected out of the X-ray cone. This mechanism simultaneously achieves a high signal size and a high signal-to-noise ratio without the need for X-ray polarization filtering, and paves the way for single-shot detection of nonlinear optical phenomena in quantum vacuum with current ultra-intense laser and X-ray technologies. Driven by strong fields, vacuum manifests itself as a nonlinear polarization medium, yet this hallmark prediction of quantum electrodynamics remains experimentally elusive for 90 years. Here, the authors uncover a super light-by-light scattering effect in vacuum, and propose an experimental scheme that holds promise for single-shot detection of this vacuum polarization effect with current technologies

The discovery of nontrivial topology in quantum critical states has revised the classification of quantum phase transitions and opened a new direction for exploiting topological phases. However, the experimental investigation of gapless many-body systems is challenging due to the inherent complex quantum entanglement. Here, we demonstrate an experimental study of the topological properties in the critical cluster Ising model on a superconducting processor with up to 100 qubits. By applying entanglement Hamiltonian tomography to the experimentally prepared low-lying states, we successfully reconstruct the reduced density matrices of the underlying ground states for subsystems with up to 12 qubits, based on which we extract the scaling dimension and central charge of the critical cluster Ising model. Furthermore, we recognize a robust two-fold topological degeneracy as well as the conformal-tower structure in the entanglement spectrum, experimentally revealing the bulk-boundary correspondence in topological critical systems. Our results demonstrate the low-lying states at critical points as useful quantum resources for investigating the interplay between topology and quantum criticality. Nontrivial topologies are long believed to survive only in gapped systems, yet recent progress suggests their existence even at quantum critical points. By preparing low-lying states on a superconducting processor up to 100 qubits and applying entanglement Hamiltonian tomography, the authors experimentally observe these nontrivial topological properties and suggest low-lying states as useful quantum resources.

Synchronization in complex networks is influenced by higher-order interactions and non-Gaussian perturbations, yet their mechanisms remain unclear. We investigate the synchronization and spike dynamics in a higher-order Kuramoto model subjected to Lévy noise. Using the mean order parameter, mean first-passage time, and basin stability, we identify boundaries distinguishing synchronization and incoherence. The stability index governs the tail heaviness of the probability density function for Lévy noise, while the scale parameter affects the magnitude. Synchronization weakens as the stability index decreases, and even completely disappears when the scale parameter exceeds a critical threshold. By varying coupling, we find bifurcations and hysteresis. Lévy noise smooths the synchronization transitions and requires stronger coupling compared to Gaussian white noise. We then define spikes as extreme excursions of the order parameter and study their statistical and spectral properties. The maximum number of spikes is observed at small-scale parameters. A generalized spectral analysis based on an edit distance algorithm measures the similarity between spike sequences and identifies spike patterns. These findings deepen the understanding of synchronization and extreme events in complex networks driven by non-Gaussian noise. Synchronization in complex networks, crucial for understanding phenomena in systems like neuronal networks and power grids, is affected by higher-order interactions and non-Gaussian perturbations. The authors explore a higher-order Kuramoto model with Lévy noise, revealing how stability and scale parameters influence synchronization, offering insights into network dynamics and extreme events.

Continuously changing environments have a paramount role in the evolution of cooperative behavior. Previous works have shown that the transitions among different games, as the feedback between behaviors and environments, can promote cooperative behavior significantly. Quantitative analysis, however, is limited to homogeneous populations, while realistic populations in nature are often more complex and highly heterogeneous. We hereby provide an analytical treatment of when the evolution of cooperation can be supported in stochastic games, applying to arbitrary spatial heterogeneity and payoff structure. We highlight that the rule and frequency of game changes can have surprisingly diverse effects on evolutionary outcomes, depending on the governing social dilemmas. While stochastic games favor the evolution of cooperation in donation games, this is not the case for public goods games and snowdrift games. Hence, our framework and model results offer a more subtle insight into the long-standing enigma. Dynamic environments influence the evolution of cooperative behavior, yet existing analyses often overlook population heterogeneity observed in realistic populations in nature. This study provides an analytical framework for stochastic games, revealing that game change dynamics can variably impact cooperation, enhancing it in donation games but not in public goods or snowdrift games, offering nuanced evolutionary insights.

Non-Hermitian physics, such as the non-Hermitian skin effect (NHSE), is well-established in classical platforms, but its emergence in intrinsically Hermitian or quantum systems remains a key challenge. Bridging this gap is crucial for connecting non-Hermitian concepts with foundational quantum many-body theory. Here, we systematically investigate this by studying a quantum subsystem with an effective non-Hermitian Hamiltonian arising from its exact frequency-dependent self-energy. We further employ complex-frequency detection, including excitation, synthesis, and fingerprint, to probe physical responses induced by complex driving frequencies. Our calculations reveal that both complex frequency excitation and synthesis are incompatible with the non-Hermitian approximation and cannot characterize the presence of the NHSE. In contrast, the complex-frequency fingerprint successfully detects the distinctive responses induced by the NHSE through the introduction of a double-frequency Green’s function. Our work provides a platform for studying non-Hermitian physics and its unconventional response in quantum systems rigorously without relying on any approximations. Non-Hermitian physics, like the non-Hermitian skin effect (NHSE), is well-explored in classical platforms but remains challenging in quantum systems. Here, the authors study a quantum subsystem described by an effective non-Hermitian Hamiltonian derived from its exact frequency-dependent self-energy, and show that only complex-frequency fingerprinting can uniquely detect NHSE-induced responses, providing a rigorous framework for exploring non-Hermitian phenomena without approximation.