Papers

Quantum random number generators are crucial for information security, yet existing implementations are hindered by bulky optics, device imperfections, and state alignment constraints. Here, using a compact metasurface platform, we achieve polarization-independent certified randomness by establishing a quantitative quantum graph framework. By mapping multi-channel nanophotonic responses onto graph vertices, we assign metasurface measurements an operational information-theoretic meaning, directly connecting weighted graph degrees to conditional min-entropy estimation. The resulting graph-certified measurements yield robust private randomness even under entanglement-based attacks without complex optics. Experimentally, we fabricate 4- and 6-channel dielectric metasurfaces to implement high-dimensional positive operator-valued measure graphs, successfully certifying randomness with heralded single photons and Poissonian light. By integrating complex quantum measurements into a single passive layer, our metasurface quantum graphs provide a scalable route for integrated quantum technologies.

We examine the impacts of dark matter (DM) on the observables of the neutron star (NS). The interaction of DM with nucleons intermediate by axion-like particles (ALPs), and the DM-admixed NS (DNS) is formulated in the framework of the relativistic mean field (RMF) formalism. The effects of the DM on the NS are characterized by two parameters: DM Fermi momentum ($q_f$) and DM mass ($m_\chi$). By varying these two parameters, we investigate how the NS's mass, radius, and tidal deformability are altered. Furthermore, we study how the ALP-mediated DM impacts the stability of the NS through the analysis of radial oscillations. In addition, the nonradial oscillation has been investigated by calculating its fundamental mode frequency in the DNS and analyzed how the ALP-mediated DM modifies its behavior.

We study classical local conserved charges obtained after finite-defect reduction of doubled four-dimensional Chern–Simons theory. At a finite simple zero, the inhomogeneous derivative term in the affine gauge transformation induced by the twist function vanishes, so the residue evaluations of the two Gaudin currents transform by the ordinary adjoint action. For each simple ideal, we use the Evans-compatible invariant tensors of the principal Drinfeld–Sokolov hierarchy as external algebraic input, construct local circle integrals, and treat the same-zero, distinct-zero, and mixed sectors separately, proving pairwise Poisson commutativity. Under the explicit assumptions of Stedman's simple-pole/simple-zero boundary Hamiltonian, the periodic trivial-monodromy sector, and boundary weights independent of phase-space variables, the reduced Hamiltonian decomposes term by term into finite-pole, infinity, finite-zero, and residual first-class-constraint contributions, which yields conservation of the constructed charges. We distinguish the finite-defect reduced space, the extended space carrying the residual constraint, and the physical quotient. The result is a conditional existence statement for a classical local Abelian Poisson subalgebra; we make no claim of functional independence, maximality, or Liouville completeness. Extensions to higher-order zeros and nontrivial monodromy sectors are outside the scope of this work.

We show that completely positive maps can be decomposed into sums of submaps which are close in completely bounded trace norm but as far apart as possible in terms of geometric channel fidelity. We then show that this kind of behavior extends to a large class of quantum channel divergences. We construct quantitative norm estimates for quantum channel divergences in terms of the Arveson-Radon-Nikodym theorem.

In astrophysical complex TAIGA there are four Imaging Atmospheric Cherenkov telescopes (IACTs), located at a distance of 300-500 m from each other, due to which extensive air showers (EAS) generated by cosmic and gamma radiation are recorded by a single telescope or by multiple telescopes simultaneously (stereo-mode). The analysis of EAS images from two or more Cherenkov telescopes together is of particular interest, since for this approach the reconstruction of physical parameters of the primary gamma ray is much more accurate than in mono-observations. However, the gamma-ray event reconstruction strongly depends on the quality of the hadron background suppression of the classifier, therefore, the gamma event selection stage is one of the important ones in the further analysis of IACT data. We propose and study several neural network methods for gamma event selection in joint TAIGA-IACT image analysis. Neural network methods we suggested involves a single-stage analysis of IACT images from two telescopes, while the second method considers the formation of autoencoder-derived essential features that contain the EAS physical parameters, including the type of primary particle.

In this PhD thesis, we take an axiomatic approach to studying multivariate divergences, which are measures of the information content of a tuple of classical or quantum states. These divergences are studied in the context of large-sample and catalytic convertibility of tuples of states. This type of convertibility is characterized by the ordering of an axiomatically defined family of divergences. In this thesis, we identify this family of divergences explicitly for two scenarios, one classical and one quantum. In the classical setting, we show that the relevant divergences are certain generalizations of the bivariate Rényi divergences. Unlike previous studies, we do not require the distributions to have the same support, yielding interesting new divergences. In the quantum setting, we consider pairs of classical-quantum states with pure component states, and find that majorization is characterized by all $\alpha$-$z$ relative entropies for $\alpha<1$. This demonstrates the first operational interpretation of these relative entropies.

Using DESI photometric catalog data, we systematically analyze the spatial alignment of star-forming galaxies (SFGs) and quiescent galaxies (QGs) in clusters. The results reveal that, in both brightest central galaxy (BCG) alignment (BA) and satellite alignment (SA), the alignment signals of SFGs and QGs exhibit opposite trends in several aspects. For the BA signal, SFGs show stronger alignment in cluster outskirts, whereas QGs exhibit stronger alignment in inner regions. For the SA signal, both SFGs and QGs exhibit nearly isotropic signals in outer regions, while in inner regions they show opposite signals. In addition, the BA signal depends on cluster richness and QG fraction, and is more pronounced in mature clusters. Specifically, QGs show a stronger BA signal overall, which increases with luminosity and axis ratio, whereas SFGs show a weaker BA signal with no significant dependence on these parameters. The BA signal also exhibits a strong dependence on satellite galaxy color, which is independent of morphology. We confirm this by analyzing the BA signal in two populations: red disk and blue elliptical galaxies. However, neither BA nor SA shows a significant dependence on redshift at z < 0.5. In summary, these findings reflect how galaxy transport along cosmic filaments drives cluster evolution: early-stage SFGs fall into clusters along filaments, and during cluster relaxation, their spatial orientations are reshaped by gravitational potentials and tidal forces, weakening BA signal and enhancing SA signal. In contrast, QGs, as early cluster members, exhibit a more pronounced anisotropic distribution and maintain relatively stable spatial orientations.

We have developed an apparatus for the measurement of the acousto-electric effect (AEE) from room temperature to liquid nitrogen temperatures. The AEE is excited by bulk acoustic waves (BAWs) for which a lithium niobate piezoelectric actuator is employed. A very low background noise level is realized through careful electrical and mechanical design of the setup. The validity of the setup is tested by measuring the AEE in heavily doped P-type and N-type silicon. The opposite sign of the AEE signal was seen for both samples, showing dependence of the signal on the type of charge carrier being dragged by acoustic waves. The signal showed quadratic dependence on the driving voltage, which is consistent with the AEE literature. Further, a temperature dependence of the AEE signal was measured, which exhibits a monotonic increase with a rise in temperature. The ability to probe the AEE in bulk samples at low temperatures makes this setup a promising tool to investigate the AEE and related phenomena in different materials at cryogenic temperatures.

High-density plasma discharges in hydrogen operating at low pressures are of considerable interest for negative ion production used in many applications. Their weak collisionality requires a kinetic, nonlocal description, and a popular approach is to model such discharges numerically using the particle-in-cell (PIC) method combined with Monte Carlo collisions (MCC). However, the most commonly used explicit momentumconserving variant of this method is highly inefficient because it must resolve both the Debye length and the plasma period. In this context, the implicit energy-conserving PIC/MCC scheme appears to be an attractive alternative, as it can model the plasmas of interest using their actual parameters without resorting to artificial scaling techniques. This work considers simulations of two types of high-density plasma discharges performed using electromagnetic or electrostatic energy-conserving PIC/MCC codes in hydrogen, and discusses the observed negative ion production.

Providing more coherent light with space-time coupling offers unprecedented opportunities across diverse scientific disciplines and areas of technology. However, in many applications, tailored laser beams with partial coherence in space and time are desired. Here, we demonstrate a programmable approach for simultaneously shaping the intensity and coherence distributions of spatiotemporally coupled partially coherent wave packets. By jointly engineering the fractal speckle of a dynamic scatterer and applying tailored modulation of the illumination function, we experimentally generate partially coherent laser beams with arbitrarily designed intensity and nontrivial coherence distributions. The proposed approach is compatible with ultrafast laser pulses, enabling the on-demand generation of partially coherent space-time wave packets. The resulting spatiotemporally partially coherent wave packets exhibit non-separable space-time intensity profiles together with engineered spatiotemporal correlation distributions. This work provides a versatile framework for tailoring partially coherent light in space and time, with varied applications in relativistic laser-matter interaction, passive imaging and optical manipulation.

Kagome superconductors AV3Sb5 (A = K, Rb, Cs) offer an outstanding platform for exploring the interplay among charge-density-wave (CDW) order, superconductivity (SC), and nontrivial topological electronic states. For CsV3Sb5, moderate hydrostatic pressure induces a double-dome superconducting phase diagram while monotonically suppressing the CDW phase, which signals an unconventional coupling between SC and CDW. Nevertheless, the microscopic nature of the pressure-modulated superconducting state and its relationship with CDW order remain poorly understood. Here we employ soft directional point-contact spectroscopy (SDPCS), combined with superconducting resistive measurements, to probe the superconducting order parameter of CsV3Sb5 under hydrostatic compression. Our anisotropic PCAR measurements resolve two distinct s-wave superconducting gaps along the c-axis and a strongly anisotropic gap within the ab plane. Two-band Blonder-Tinkham-Klapwijk (BTK) fits to the c-axis spectra yield a large gap satisfying 2Delta1/kBTc > 3.52 and a small gap with 2Deltas/kBTc < 3.52. The spectral-weight-averaged coupling ratio 2Deltaavg/kBTc is enhanced in the pressure window between P1 and P2, suggesting that pressure-induced modifications of the low-energy electronic structure may contribute to the evolution of superconductivity. For ab-plane junctions, the superconducting gap anisotropy is gradually suppressed above P1, accompanied by the emergence of a pronounced peak-dip-hump structure suggestive of enhanced coupling between superconducting quasiparticles and a bosonic excitation. These results shed new light on the intricate entanglement between CDW and SC in kagome superconductivity.

We present a nonabelian complex self-dual antisymmetric tensor model, with gauged internal symmetry, comprising a complex multiplet of massless self-dual antisymmetric tensor fields and its conjugate (interacting with massless Yang-Mills gauge fields). We build the model at the classical level, via a first order formulation, assigning local fields to a component expansion over the Dirac algebra and a basis of internal matrices, with Lorentz and gauge invariance ensured by tracing, and applying an appropriate bilinear form. The full expansion requires auxiliary place-holder fields, which are not potentials, but become curvatures (field strengths) after elimination via their algebraic equations of motion. The component expansion over the Dirac algebra is closed under multiplication by additional internal matrices, which are not gauge group generators, but mix internal components, and link auxiliary curvatures with potentials. The model is shown to be invariant under such transformations, and thus possesses a type of hidden internal symmetry. We analyze the specific case of gauge group $SU(2)\! \times \! U(1)$, and as higher symmetry candidates, we consider both the Lie group $SU(3)$ and the Lie superalgebra $SU(2/1)$ (with the additional matrices acting via Lie brackets, or graded Lie brackets, respectively).

The anomalous Hall effect (AHE) in unconventional magnets has attracted considerable attention. A giant AHE has recently been observed in the candidate $p$-wave magnet Gd$_3$(Ru$_{1-\delta}$Rh$_{\delta}$)$_4$Al$_{12}$ [Nature 646, 837(2025)], while its theoretical interpretation invokes a spontaneous magnetization to break time-reversal symmetry ($\mathcal{T}$), although the magnetic order itself already breaks $\mathcal{T}$. Consequently, the microscopic origin of the AHE in odd-parity magnets (OPMs) remains an open question. Here we establish the symmetry condition and microscopic mechanism for the AHE in OPMs. Since the OPM order is classified by the spin group whereas the AHE is governed by the magnetic group, the AHE is allowed only when the magnetic point group is ferromagnetic; conversely, it is forbidden whenever the effective time reversal $\mathcal{T}\tau$ (with $\tau$ a fractional translation), which is essential to the realization of the OPM, is preserved. Microscopically, OPMs generically host a hidden Zeeman field (HZF) rooted in this intrinsic $\mathcal{T}$ breaking, and its interplay with spin-orbit coupling (SOC) generates the AHE without any external field. We demonstrate this picture with models on the square, honeycomb, and kagome lattices. In particular, a square-lattice helimagnet with sublattice-resolved SOC maps exactly onto an anisotropic Rashba–Zeeman model, whose Zeeman term is nothing but the HZF and directly yields the AHE. Our results establish the symmetry condition for the AHE in OPMs and identify the HZF–SOC interplay as a general route to realize it.

In this paper, we derive the spin polarization and the spin Chern number in momentum and real spaces in terms of the Wilson loop in each spin sector. For these derivations, the spin matrix in the subspace of occupied or unoccupied states is generalized by the unitary rotation to prevent the spectral gap from closing. In the presence of a finite spin gap, the spin eigenvectors recompose the eigenstates of the Hamiltonian in two spin sectors. A dimensional reduction leads to the charge polarization in each spin sector in terms of the Wilson loop along the effective Brillouin zone (BZ) in one dimension (1D). A linear combination of the charge polarizations defines the spin polarization, which naturally quantifies the spin Chern number in momentum space. It is also shown that the spin Chern number is directly derived from the local Wilson loops on a discrete 2D BZ. The theoretical treatment is further generalized for real space in a supercell framework, which can deal with ordered and disordered systems in a unified manner. In this framework, the spin Chern number in real space is formulated in terms of the Wilson loop around the BZ boundary. These formulations are used to numerically evaluate topological phases in the Bernevig-Hughes-Zhang model. Numerical results show an equivalence of the spin Chern number and the ${\mathbb{Z}_2}$ index.

We study classical Bopp–Podolsky (BP) electrodynamics on four-dimensional de Sitter spacetime, focusing on its transverse retarded Green function and gauge-invariant electromagnetic response. Because de Sitter spacetime is maximally symmetric, its vector Green functions admit a covariant expansion in a finite basis of invariant bitensors, with scalar coefficients depending only on the invariant separation. For conserved sources, the fourth-order field operator factorizes into Maxwell and massive-vector operators, yielding the BP retarded kernel as the difference of their transverse Green functions. Using the invariant bitensor decomposition, we reduce the propagator equations to a hypergeometric master equation and determine the distributional structure of its solution. The common leading short-distance singularity of the Maxwell and massive-vector sectors cancels, leaving a logarithmic master singularity and a softened vector-potential wavefront. After one curl, the gauge-invariant field-strength kernel contains a null-cone delta distribution and a regular timelike tail. The smooth Maxwell master tail is annihilated by the curl, so the interior electromagnetic tail is generated entirely by the massive sector. We also derive an exact horizon-regular static potential, demonstrate the cancellation of the Coulomb divergence, recover the flat-space BP potential, and formulate the generalized Gauss law. On global de Sitter spacetime, the compactness of the spatial sections requires the total charge to vanish; we implement this constraint using an antipodal charge configuration with smooth factorized initial data. The analysis is classical and does not assume a quantum Lee–Wick contour or a preferred de Sitter vacuum.

Originally coined 100 years ago to represent a shear-reversible sol-gel transition, the range of the term "thixotropy" has gradually expanded to encompass time-dependent changes in viscosity. Since this risks confusing "thixotropy" with ordinary nonlinear viscoelastic behavior, in this work we seek simple, historically faithful, quantifiable, and experimentally testable definitions of "thixotropy" that avoid this confusion. By analysing both historical tradition and published experimental data, we arrive at three complementary definitions. Definition 0 provides an idealized, purely inelastic reference useful primarily for recognizing thixotropy in a constitutive equation. Definitions 1 and 2, which are more practical, require, respectively, unusually large strains to reach steady state, and unbounded growth of the material relaxation time during rest. Definition 1 can apply in either shear-rate or stress-controlled modes, with the latter encompassing the so-called "viscosity bifurcation." These criteria are tested across diverse materials that we identify as thixotropic based on their responses clearly exceeding their viscoelastic reference scales. The framework is deliberately phenomenological and does not require specific microscopic mechanisms, allowing diverse materials to be described within a common rheological language, as is typical for rheological terminology. We believe that these definitions provide a practical framework for assigning thixotropy a more definite place in rheological taxonomy.

Morphogenesis is driven by the interplay of genetic regulation and tissue mechanics. In vivo video data is limited, particularly under genetic mutations and environmental perturbations, making generalization beyond the most representative conditions in the dataset challenging. However, at tissue scales, the dynamics of Drosophila can be described as a continuum flow, motivating the usage of representations learned across other physical systems as priors for developmental dynamics. We investigate finetuning Walrus, a Continuum Dynamics Foundation Model pretrained across a broad set of simulated continuous systems, on tissue velocity fields from only 12 wild-type Drosophila blastoderm videos. We evaluate autoregressive prediction both in-distribution and zero-shot under unseen temperature and genetic perturbations. Zero-shot refers to evaluation on perturbation conditions never seen during wild-type finetuning, without any additional training. In-distribution, a Fourier Neural Operator model trained from scratch achieves best performance on VRMSE. However, Walrus (CRPS) is the strongest model under the most severe distribution shift of unseen samples of mutated embryos and temperature conditions. Interestingly, predictions capture the shape of the mean surface tissue velocity trajectory and its separation between 17{\deg}C and 27{\deg}C, including the timing of the peak at Germ Band Extension onset, a biologically meaningful milestone of embryo development. Our results provide preliminary support that representations learned from different dynamical systems can transfer to experimental morphogenesis in developmental regimes, provided they admit a continuum description. More broadly, our results motivate further study of physics foundation models as a new complementary tool for the simulation of morphogenesis in low-data regimes.

We propose to measure hard exclusive $\alpha$-knockout reactions from the light $\alpha$-conjugate nuclei $^{12}$C, $^{16}$O, and $^{20}$Ne using electron scattering. Three reaction channels will be measured for the first time on the same target set: (i) the quasi-elastic knockout $(e, e' \alpha)$ knockout, which establishes a baseline against $\alpha$-clustering model calculations and tests final-state-interaction (FSI) models; (ii) coherent deeply virtual Compton scattering (DVCS) on a bound $\alpha$, which provides a quark-level probe of the bound system through the beam-spin asymmetry; and (iii) coherent vector-meson production ($\phi$ and J/{$\psi$}) on a bound $\alpha$, which probes the gluon distribution of the bound cluster through two-gluon exchange. The central observables are ratios of cross sections and beam-spin asymmetries between the bound $\alpha$ in $^{12}$C, $^{16}$O, and $^{20}$ Ne and the free $^4$He ground state. Together these measurements directly address the question of the role of QCD in the structure of light nuclei : do the quark and gluon distributions of an $\alpha$ embedded in a heavier nucleus differ from those of a free 4He, and do those modifications track the increasing $\alpha$-clustering strength along the $\alpha$-conjugate chain? The measurement will use the 12 GeV CEBAF accelerator in Hall B with the CLAS12 spectrometer instrumented with the ALERT low-energy recoil detector and high-pressure gas straw targets. ALERT, which replaced the CLAS12 silicon vertex tracker, was successfully commissioned and operated during Run Group L (RG-L) from April through August 2025. It uniquely provides identification of low-momentum recoiling light ions (p, d, t, $^3$He, and $^4$He) close to the beamline at the high luminosities required by these exclusive channels.

Genuine multipartite entanglement (GME) is a valuable resource for quantum technologies, but quantifying it in many-body systems can be demanding since measures defined through optimizations over bipartitions are often assumed to require large joint measurements and many measurement settings. We introduce the concepts of GME evaluation length and GME evaluation number, which capture, respectively, the largest subsystem that must be jointly measured and the number of distinct subsystems that need to be measured to evaluate multipartite entanglement measures defined via bipartition optimizations. Taking the genuine multipartite concurrence (GMC) as a canonical example, we show that, for $N$-qubit Haar-random pure states, the GMC can be evaluated using only $N$ single-qubit purity measurements. Thus, for typical many-body states, evaluating the GMC requires considering only the $N$ single-site bipartitions, rather than the exponentially many distinct bipartitions. We further corroborate this behavior numerically for physically accessible states generated by local random quantum circuits. Our results show that the practical cost of quantifying GME can be dramatically lower than suggested by its formal definition, establishing measurement complexity as a complementary operational lens for multipartite entanglement.

A one-dimensional waveguide is a crucial medium for transferring propagating quantum information between remote qubits, yet the photon-mediated interaction is typically fixed by the static device geometry, qubit parameters, and their couplings to the transmission line. Such an interaction can be engineered to be coherent or dissipative via virtual- or real-photon exchange, respectively, yet its effective strength remains fixed in either case. Here we demonstrate dynamical control over this interaction by applying Floquet engineering to two superconducting qubits coupled to a waveguide terminated by a capacitive mirror. By positioning one qubit at an antinode and the other qubit at a node or an antinode of the resonant standing wave, we realize a Hermitian or non-Hermitian coupling between the two qubits. A periodic flux drive of the qubit frequencies then enables on-demand control of the coherent energy splitting and the collective decay. Our results establish Floquet engineering as a route to dynamically reshape both coherent and dissipative photon-mediated interactions between remote quantum emitters.

The Tarski fixed-point problem asks for a fixed point of a monotone map on a $k$-dimensional grid lattice of width $n$ and has applications in game theory, economics, and verification. Substantial gaps remain between the known upper and lower bounds on its quantum query complexity. We prove two hardness bootstrapping theorems for quantum query lower bounds. Starting from a hard instance family whose instances have pair-wise incomparable unique fixed points, and a lower bound established by the nonnegative adversary method, we bootstrap this lower bound by (i) a factor of $\Omega(t)$ when the dimension is multiplied by $t$ and the width remains unchanged, and (ii) a factor of $\Omega(\log m)$ when the width is multiplied by $m$ and the dimension is doubled. Applying these theorems, we obtain three consequences: (i) an $\Omega(k\log^2 n)$ lower bound for $k\geq 4$, improving previously best-known classical and quantum lower bounds; (ii) for every fixed constant $\alpha>0$, there exists a constant $\delta(\alpha)>0$ such that $Q_\epsilon(\text{Tarski}(n,k))=\Omega(kn^{\delta(\alpha)})$ whenever $k>n^\alpha$, and in particular, an $\Omega(kn^{0.0072})$ lower bound for $k>n^{2/203}$, the first lower bound with simultaneous linear dependence on the dimension and polynomial dependence on the width; and (iii) a superpolynomial lower bound of $(k/\log k)^{\Omega(\log k)}$ for exponentially wide grids, where $n=2^{\Theta(k)}$. The last result rules out a route to polynomial-time algorithms for simple stochastic games and ARRIVAL through generic polynomial-query black-box Tarski solvers.

Let $P$ be a short-range projector on $\ell^2(\mathbb{Z}^{2n},\mathbb{C}^m)$ and $U=(U_1,\dots,U_{2n})$ be a transverse family of open subsets of $\mathbb{R}^{2n}$. We give an elementary proof of a recent result of Martinian-Stoiber, which extends a two-dimensional result of Drouot-Zhu to all even dimensions. Specifically, using only Stokes' theorem and the Poincaré lemma, we show that the geometric Kubo formula $\operatorname{Tr}\big(P[P,\mathbf{1}_{U_1}]\wedge\cdots\wedge[P,\mathbf{1}_{U_{2n}}]\big)$ is the product of a topological integer $\mathcal{X}_U$, which depends only on the relative positions of $U_1, \dots, U_{2n}$, and of the bulk conductance of $P$. Our proof writes the geometric bulk conductance as the pairing of $P$ with a cochain on $\mathbb{Z}^{2n}$ - an idea originally due to Kitaev - and deforms the cochain rather than the sets $(U_1, \dots, U_{2n})$. The proof presented in this paper is due to Claude Opus 5.5.

Deterministic preparation of bosonic resource states is a central task in continuous-variable quantum information processing and quantum metrology. Here we develop a measurement-based imaginary time evolution (MITE) protocol for preparing squeezed and non-Gaussian states. The protocol combines ancilla-mediated weak measurements of the Hamiltonian with a conditional phase rotation that suppresses excited state trapping and stabilizes convergence toward the ground state. The method is potentially applicable in hybrid discrete variable-continuous variable (DV-CV) platforms, where the qubit acts as the measurement readout. We demonstrate deterministic convergence over a broad range of parameters and show that the performance degradation near the stability boundary is governed by the shrinking Bogoliubov quasiparticle gap. The same framework also extends to non-Gaussian bosonic resource states, including Schrödinger cat states and excited states of the single-mode squeezing Hamiltonian, which display Wigner negativity. The squeezed states remain robust under bosonic loss over experimentally relevant regimes.

We study the intrinsic 0.5–2~keV emission of the hot circumgalactic medium (CGM) in the IllustrisTNG simulation TNG100-2 at redshifts 0, 0.1, and 0.2. We calculate the emission of gas cells with $T \geq 10^6$~K in the spherical shell between $0.15R_{500}$ and $R_{500}$ and compare samples selected by their star-formation activity. X-ray luminosity increases with halo mass, although the class-dependent fits cover different mass intervals. Among galaxies with positive luminosity and star formation rate (SFR), the high-activity sample retains a positive association after a linear adjustment for halo mass. The residual association is weaker in the quiescent subset with positive luminosity and SFR. Within $10^{11.75}<M_{500}/M_\odot<10^{12.25}$, the high-activity sample has more centrally concentrated emission and a median luminosity about five times that of the quiescent sample. The two populations have similar median hot-gas masses despite their different X-ray luminosities and radial profiles. These differences are consistent with variations in the spatial distribution and thermodynamic state of the emitting gas, although the samples are not matched in halo mass. Our results suggest that soft X-ray emission probes the structure of the hot CGM as well as its gas content, offering a way to investigate how star formation and feedback shape gaseous halos.

Quantum teleportation, a key building block for quantum technologies, enables distant parties, Alice and Bob, to transfer an unknown quantum state using entanglement, local operations, and classical communication. In this work, we propose a quantum teleportation protocol for single-photon time-frequency continuous variables, where time is the time of arrival at a detector. We detail the operational requirements of the protocol, notably the nonlinear interactions needed for the photon-photon time-frequency entangling gate. By explicitly treating the detector position as the reference frame for time of arrival, we show that, even with ideal classical and quantum channels, the input-output fidelity is not unity unless the receiving party can correct the detector-position mismatch. This results in a trade-off between teleportation fidelity and the temporal bandwidth of the input photon wavepacket. The protocol itself can be used for remote detector synchronization. In particular, we show that time-frequency cat and Gottesman-Kitaev-Preskill states provide an internal temporal ruler through fidelity revivals. We further derive the classical and best-copy fidelity thresholds for single-photon Gaussian wavepackets, finding that the relevant vacuum-equivalent shot noise is input-dependent, in contrast with quadrature-based continuous-variable quantum teleportation. Our proposal derives from a quantum theory of space-time events, whereafter we establish space as a reference for the time degree of freedom, thereby grounding our work in ongoing research on reference frames and superselection rules in quantum optics and quantum information. Beyond protocols harnessing time-frequency continuous variables of single photons, this work points toward remote synchronization in quantum communication architectures.

Uniform orbital detuning can restore spatial extent even as quasiperiodic modulation strengthens. In a trimer ladder with fixed hoppings and orbital modulation signs, increasing detuning and modulation amplitude together drives successive avoided crossings that redistribute orbital weights, suppressing the projected onsite potential in both lower molecular bands while leaving the third strongly modulated. Complete-band participation scaling supports two reentrant high-participation windows, with wave-packet propagation corroborating spatial recovery at representative controls over the studied sizes and times. These diagonal cancellations leave residual interband modulation, which generates a self-energy whose magnitude depends on the molecular level separation. Gaussian quadrature improves convergence of closed-walk determinant estimates used to cross-check energy-resolved attenuation. Comparing the coupled and decoupled ladders under the same finite-size participation criterion shows that restoring the full off-diagonal modulation narrows both sampled windows, with a larger absolute contraction of the second.

One of the unsolved questions in astrophysics and cosmology is the development of a robust physical model to explain the thermal history of the intergalactic medium during the epoch of reionization. Various astrophysical models have been proposed, but current models remain only partially constrained by available observations. To clarify this ambiguity, hydrodynamical, semi-numerical, and N-body simulations can help solve this issue. One notable simulation from the epoch of reionization is the 21SSD simulations, which provide high-resolution results for the global 21-cm brightness temperature and the 21-cm power spectrum during the epoch of reionization. The simulation includes 45 models spanning three key astrophysical parameters of X-ray emissivity, Lyman-band emissivity, and the X-ray hard-to-soft emissivity ratio. Distinct values of these parameters result in different models of this simulation. In this work, four active radio observatories, including HERA, MWA, GMRT, and LOFAR have been considered to investigate the sensitivity and thermal noise of the 21-cm power spectrum. Each observatory has a particular sensitivity based on its instrumental characteristics, which helps assess which models lie above the forecast sensitivity thresholds of current instruments.

Mn$_3$Sn exhibits a complex magnetic phase diagram with multiple symmetry-breaking phenomena. Minute electron doping at the Mn site breaks the kagome lattice symmetry in Mn$_3$Sn. In this work, we exploited this to tune the order of the magnetic phase transition using magnetocaloric effect in Mn$_{3-x}$Co$_x$Sn single crystals. Pristine Mn$_3$Sn shows metallic behaviour with a spin-reorientation transition at 278 K, which shifts to 175 K upon Co doping. Additionally, Co doping also induces a weak-ferromagnetic transition near $\approx 210$ K. The effect of Co doping results inverse to conventional magnetocaloric effect, with enhanced magnetic entropy change. Further, the scaled entropy change reveals a field-driven magnetic phase transition crossover from first order to second order in Mn$_{2.75}$Co$_{0.25}$Sn crystal. Based on experimental data, a new phase diagram is constructed, depicting the field evolution of various magnetic orders.

Active matter systems composed of self-propelled entities exhibit a wide range of out-of-equilibrium phase behaviors and collective dynamics. Assemblies of active particles, e.g., in a linear structure, are particularly interesting, as they exhibit an intriguing interplay between activity and geometrical restrictions due to self-avoidance and entanglements. Using Langevin dynamics simulations of an active Brownian ring polymer with translational and rotational inertia, we uncover an inertia-driven re-entrant coil-globule transition in the absence of any attractive interactions. We show that rotational inertia plays a paramount role, leading, in the globular state, to spontaneous, nonzero, radially outward polarization of the active forces. Self-avoidance and entanglements break the rotational symmetry of active beads and effectively stabilize the globular states. The transition becomes increasingly sharp with increasing rotational inertia, yielding highly compact globular conformations at intermediate activities, whereas at high activity the polymer re-expands into a coil state. Scaling of the radius of gyration reveals crossovers from self-avoiding, phantom-like to compact-globular structures. Further, rotational inertia enhances transport properties, with an intermediate activity-induced Rouse-type bead diffusion and a long-time diffusion coefficient displaying a power-law dependence on the moment of inertia. Our study establishes a purely inertia-induced mechanism for controlling the collapse of active polymers, arising from spontaneous active-force polarization and self-avoidance.

Flat bands amplify interactions into correlated phases, and topological bound states are robust by principle; combining the two in a model that is both exactly analyzable and experimentally accessible is therefore especially desirable. Here we show that a square-lattice model with a slowly modulated Dirac mass texture, $m(x)=m+m_0\cos(2\pi x/L)$ with $L$ up to hundreds of sites, provides such a setting, without engineered geometries, lattice-scale textures, or long-range hoppings. Exact nesting reduces the problem, independently at each transverse momentum $k_y$, to a $1+1$ dimensional Dirac Hamiltonian with a position-dependent mass: every simple zero of $m(x)$ binds Jackiw-Rebbi zero modes, and the two walls of a period form an effective Su-Schrieffer-Heeger ring. The model interpolates between a chirally pinned flat band at large $L$, a helical miniband whose nodes are enforced by a boundary phase of the ring, and a bias-dimerized regime in which the sign of the bias sets a winding number. A central result is that the miniband bandwidth is not a single scale: a max-min measurement conflates three widths of different origin, the helical height $W_{\rm JR}$ exponential in the period, the zone-edge upturn $W_{\rm edge}\propto L^{-2/3}$ dominating at large $L$, and a bias bump exponential in $L$, so the flat band is robust against bias in the thermodynamic limit. We analyze two lattice realizations, a two-orbital model with modulated inter-orbital hybridization and a single-orbital bond-order texture sharing the nodal physics while leaving the van Hove points gapless, and propose experiments on cold-atom superlattices, Kekule-ordered graphene, STM designer lattices, and microwave arrays.