We propose a universal framework for classifying quantum states based on their scale-resolved correlation structure. Using the recently introduced information lattice, which provides an operational definition of the total amount of correlations at each scale, we define intrinsic characteristic length scales of quantum states. We analyze ground and midspectrum eigenstates of the disordered interacting Kitaev chain, showing that our framework provides a novel unbiased approach to quantum matter.

Dissipative systems with decoherence-free subspaces, also known as dark spaces (DSs), can be used to protect quantum information. At the same time, dissipation is expected to give rise to coherent information degradation outside the DS. Employed to support quantum information platforms, DSs can be adiabatically modified in a way that resembles adiabatic control of coherent systems. Here we study the slow evolution of a purely dissipative system with a spectral gap $\gamma$, characterized by a strong symmetry, under a cyclic protocol with period $T$. Nonadiabatic corrections to the state evolution give rise to decoherence: the evolution within the instantaneous DS is described by a time-local effective Liouvillian operator that leads to purity degradation over a period, of order $1/\gamma T$. We obtain a closed form of the latter to order $1/(\gamma T{)}^2$. Our analysis underlines fundamental limitations of coherent quantum information processing in the absence of corrective measures.

We investigate quantum-enhanced metrology in a triple point criticality and discover that quantum criticality does not always enhance measurement precision. We have developed suitable adiabatic evolution protocols to effectively restrain excitations, which could accelerate the adiabatic evolutions and lead to an exponential super-Heisenberg scaling. This scaling behavior is quite valuable in practical parameter estimating experiments with limited coherence time. Dissipation can strengthen the super-Heisenberg scaling until decoherence increases to dominate in the dissipative dynamics. Additionally, measurement precisions beyond Heisenberg scaling can be experimentally achieved in the trapped ion system. Our findings strongly indicate that criticality-enhanced metrology can indeed significantly enhance measurement precisions to a super-Heisenberg scaling when combining a triple point and beneficial parameter modulations, which will be conducive to the exploration of other super-Heisenberg scaling and their applications.

Secondary cosmic ray fluxes are important probes of the propagation and interaction of high-energy particles in the Galaxy. Recent measurements of primary and secondary cosmic ray nuclei have revealed unexpected spectral features that demand a deeper understanding. In this work we report the direct measurement of the cosmic ray boron spectrum from $10\mathrm{GeV}/\mathrm{n}$ to $8\mathrm{TeV}/\mathrm{n}$ with eight years of data collected by the Dark Matter Particle Explorer (DAMPE) mission. The measured spectrum shows a hardening at $182\pm 24\mathrm{GeV}/\mathrm{n}$ with a spectral index of ${\gamma }_1=3.02\pm 0.01$ before the break and an index change of $\mathrm{\Delta }\gamma =0.31\pm 0.05$ after the break. A simple power law model is disfavored at a confidence level of $8\sigma$. Compared with the hardenings measured in the DAMPE proton and helium spectra, the secondary boron spectrum hardens roughly twice as much as these primaries, which is consistent with a propagation related mechanism to interpret the spectral hardenings of cosmic rays observed at hundreds of $\mathrm{GeV}/\mathrm{n}$.

We introduce cobra (Cosmology with Optimally factorized Bases for Rapid Approximation), a novel framework for rapid computation of large-scale structure observables. cobra separates scale dependence from cosmological parameters in the linear matter power spectrum while also minimizing the number of necessary basis terms $N_b$, thus enabling direct and efficient computation of derived and nonlinear observables. Moreover, the dependence on cosmological parameters is efficiently approximated using radial basis function interpolation. We apply our framework to decompose the linear matter power spectrum in the standard $\mathrm{\Lambda }\mathrm{CDM}$ scenario, as well as by adding curvature, dynamical dark energy and massive neutrinos, covering all redshifts relevant for Stage IV surveys. With only a dozen basis terms $N_b$, cobra reproduces exact Boltzmann solver calculations to $\sim 0.1\%$ precision, which improves further to $\sim 0.02\%$ in the pure $\mathrm{\Lambda }\mathrm{CDM}$ scenario. Using our decomposition, we recast the one-loop redshift space galaxy power spectrum in a separable minimal-basis form, enabling $\sim 4000$ model evaluations per second at $\sim 0.02\%$ precision on a single thread. This constitutes a considerable improvement over previously existing methods (e.g., FFTLog) opening a new window for efficient computations of higher loop and higher order correlators involving multiple powers of the linear matter power spectra. The resulting factorization can also be utilized in clustering, weak lensing, and CMB analyses.

Models of scalar field dark matter where the scalar is a dilaton have a special behavior, since nontrivial couplings, $d$, to matter result in a contribution to the potential for the field that is proportional to the trace of the stress-energy tensor. We look in more detail at the dilaton mass, $m_{\varphi }$, and initial conditions required to yield the correct relic abundance for couplings that are not already excluded by terrestrial experiments. In minimal models with only couplings accessible to terrestrial searches, we find that dilaton dark matter with $m_{\varphi }\gtrsim {10}^{-10}\mathrm{eV}$ requires couplings suppressed compared to constraints from equivalence principle tests and fifth force searches in order to not produce too much dark matter, improving on the strongest current experimental constraints by up to $\sim \mathcal{O}(10)$, with consequences for the proposed mechanical resonator dilaton dark matter searches. In nonminimal or universally coupled models, the unconstrained couplings of the dilaton to, e.g., the top quark can strongly influence the relic abundance at all masses. In particular, this implies that atom interferometry searches at masses $m_{\varphi }\approx {10}^{-19}\mathrm{eV}$ are unable to constrain the early Universe behavior or UV physics of the dilaton. We also find that dilatonic couplings allow for compatibility of $m_{\varphi }\gtrsim {10}^{-7}\mathrm{eV}$ with an observably large tensor-to-scalar ratio in the cosmic microwave background, which is not possible for a decoupled scalar of the same mass.

We construct a $(1+1)\mathrm{d}$ gapless theory which has Haagerup ${\mathcal{H}}_3$ symmetry. The construction relies on the recent exploration of the categorical Landau paradigm applied to fusion category symmetries. First, using the symmetry topological field theory, we construct all gapped phases with Haagerup symmetry. Extending this construction to gapless phases, we study the second order phase transition between gapped phases, and determine analytically a Haagerup-symmetric conformal field theory. This is given in terms of two copies of the three-state Potts model, on which we realize the full ${\mathcal{H}}_3$ symmetry action and determine the relevant deformations to the ${\mathcal{H}}_3$-symmetric gapped phases. This continuum analysis is corroborated by a lattice model construction of the gapped and gapless phases, using the anyon chain.

We study the energy structures of muonic Ar atoms and find the muon orbital collapses at a critical angular momentum $l_c$ using density-functional theory (DFT). The $l_c$ may provide an upper limit for the muon-captured states in muon-Ar collisions. We confirm the existence of this upper limit by calculating the state-specified capture probability using the time-dependent Schrödinger equation (TDSE) and the classical trajectory Monte Carlo (CTMC) method with the single-active-particle approximation. Modifying the mapping between the classical orbital energy and the principal quantum number led to a reasonable agreement in the state-specified muon capture probabilities obtained by the TDSE and CTMC methods. We propose a simple method to estimate $l_c$ for exotic noble atoms from atomic model potentials. The estimated values agree with those calculated by DFT.

Dipole-bound states of cryogenically cooled phenoxide anions (deprotonated phenol) have been investigated by combining trapping in a 6 K ion trap and subsequent action-absorption spectroscopy in an ion-storage ring. As action we consider creation of neutral phenoxy radicals. A multitude of dipole-bound resonances, not previously observed, are assigned to vibrations in the phenoxyl radical core molecule. By using the storage ring, we include prompt as well as delayed $\mathrm{\mu }\mathrm{s}$ light-induced action. The dipole-bound states decay primarily by prompt action (faster than $10\mathrm{\mu }\mathrm{s}$), but some resonance states live longer than $10\mathrm{\mu }\mathrm{s}$. This suggests that in addition to vibrational autodetachment, internal conversion with subsequent thermionic emission from a hot electronic ground state may be operative. The resonances associated with the delayed decay are red-shifted relative to those of the faster (prompt) decay, which may imply that rotations play a role for the excited-state dynamics.

Topological physics provides novel insights for designing functional photonic devices, such as magnetic-free optical diodes, which are important in optical engineering and quantum information processing. Past efforts mostly focus on the topological edge modes in two-dimensional (2D) photonic Chern lattices, which, however, require delicate fabrication and temporal modulation. In particular, the 1D nonreciprocal edge mode needs to be embedded in a 2D lattice, contradicting with the compactness of integrated photonics. To address these challenges, we investigate the optical nonreciprocity of the 1D Su-Schrieffer-Heeger (SSH) superradiance lattices in room-temperature atoms. The probe fields propagating in two opposite directions perceive two different SSH topological phases, which have different absorption spectra due to the interplay between the Zak phase and the thermal motion of atoms, resulting in optical nonreciprocity. Our findings reveal the relationship between 1D topological matter and optical nonreciprocity, simplifying the design of topologically resilient nonreciprocal devices.

Synchronization of oscillators is ubiquitous in nature. Often, the synchronized oscillators couple directly, yet in some cases synchronization can arise from their parametric interactions. Here, we theoretically predict and experimentally demonstrate the parametric synchronization of a dissipative Kerr soliton frequency comb. We specifically show that the parametric interaction between the soliton and two auxiliary lasers permits the entrainment of the frequency comb repetition rate. Besides representing the first prediction and demonstration of parametric synchronization of soliton frequency combs, our scheme offers significant flexibility for all-optical metrological-scale stabilization of the comb.

In topological physics, it is commonly understood that the existence of the boundary states of a topological system is inherently dictated by its bulk. A classic example is that the surface Fermi-arc states of a Weyl system are determined by the chiral charges of Weyl points within the bulk. Contrasting with this established perspective, here, we theoretically and experimentally discover a family of topological chiral bulk states extending over photonic Weyl metamaterial waveguides, solely induced by the waveguide boundaries, independently of the waveguide width. Notably, these chiral bulk states showcase discrete momenta and function as tunnels that connect Fermi-arc surface states living in different two-dimensional spaces via a third dimension. Our work offers an alternative mechanism for robust chiral bulk transport of waves and highlights the boundaries as a new degree of freedom to regulate bulk Weyl quasiparticles.

Altermagnetism, a type of magnetic order that combines properties of ferro- and antiferromagnets, has stirred great interest lately, not only as a promising source of spintronics applications, but also as a potential gateway to exotic phases of matter. Here, we demonstrate how to generalize collinear altermagnetism to $\mathrm{SU}(N)$ magnets with $N>2$. Guided by symmetry principles, we present a recipe to construct Heisenberg models for such generalized altermagnets and apply it explicitly for $N=3$, 4. Using flavor-wave theory, we compute the excitation spectrum of a two-dimensional SU(3) model and show that it exhibits magnon bands with altermagnetic splitting according to magnetic quantum numbers; we connect this quantum-number splitting to the frequently used concept of magnon chirality. We also compute the electronic band structure for a metallic system of the same symmetry and map out the polarization of the resulting flavor-split bands.

A beyond electric-dipole light-matter theory is needed to describe emerging x-ray and THz applications for characterization and control of quantum materials but inaccessible as nondipole lattice-aperiodic terms impede on the use of Bloch’s theorem. To circumvent this, we derive a formalism that captures dominant nondipole effects in intense electromagnetic fields while conserving lattice translational symmetry. Our approach enables the first accurate nondipole first-principles microscopic simulation of nonperturbative harmonic generation in Si. We reveal nondipole-induced transverse currents generating perturbative even-ordered harmonics and display the onset of nondipole high harmonic generation near the laser damage threshold.

The precession protocol involves measuring $P_3$, the probability that a uniformly precessing observable (like the position of a harmonic oscillator or a coordinate undergoing spatial rotation) is positive at one of three equally spaced times. Tsirelson’s inequality, which states that $P_3\le 2/3$ in classical theory, is violated in quantum theory by certain states. In this Letter, we address some open questions about the inequality: What is the maximum violation of Tsirelson’s inequality possible in quantum theory? Might other theories do better? By considering the precession protocol in a theory-independent manner for systems with finitely many outcomes, we derive a general bound for the maximum possible violation. This theory-independent bound must be satisfied by any theory whose expectation values are linear functions of observables—which includes classical, quantum, and all general probabilistic theories—and depends only on the minimum positive and negative measurement outcomes. Given any such two values, we prove by construction that quantum theory always saturates this bound. Some notable examples include the angular momentum of a spin-$3/2$ particle and a family of observables that outperform the quantum harmonic oscillator in the precession protocol. Finally, we also relate our findings to the recently introduced notion of constrained conditional probabilities.