Controlling magnetism using voltage is highly desired for applications, but remains challenging due to a fundamental contradiction between polarity and magnetism. Here, we propose a mechanism to manipulate magnetic domain walls in ferrimagnetic or ferromagnetic multiferroics using the electric field. Different from those studies based on static domain-level couplings, here the magnetoelectric coupling relies on the collaborative spin dynamics around domain walls. Accompanying the reversal of spin chirality driven by polarization switching, a “rolling-downhill”-like motion of the domain wall is achieved in nanoscale, which tunes the magnetization locally. Our mechanism opens an alternative route to the pursuit of practical and fast converse magnetoelectric functions via spin dynamics.

Dense granular flows are well described by several continuum models; however, their internal dynamics remain elusive. This study explores the contact force distributions in simulated steady and homogenous shear flows. The results demonstrate the existence of high magnitude contact forces in faster flows with stiffer grains. A proposed physical mechanism explains this rate-dependent force transmission. This analysis establishes a relation between contact forces and grain velocities, providing an entry point to unify a range of continuum models derived from either contact forces or grain velocity.

We present first results of resumming soft gluon effects in a simulation of high-energy collisions beyond the leading-color approximation. We work to all orders in QCD perturbation theory using a new parton branching algorithm. This amplitude evolution algorithm resembles a parton shower that is able to systematically include color-suppressed terms. We find that color-suppressed terms can significantly contribute to jet veto cross sections.

We perform the global analysis of polarized semi-inclusive deep inelastic scattering (SIDIS), pion-induced polarized Drell-Yan (DY) process, and $W^{\pm }/Z$ boson production data and extract the Sivers function for $u$, $d$, $s$ and for sea quarks. We use the framework of transverse momentum dependent factorization at next-to-next-to-next-to leading order (${\mathrm{N}}^3\mathrm{LO}$) accuracy. The Qiu-Sterman function is determined in a model independent way from the extracted Sivers function. We also evaluate the significance of the predicted sign change of the Sivers function in DY process with respect to SIDIS.

Collimated sprays of hadrons, called jets, are an emergent phenomenon of quantum chromodynamics (QCD) at collider experiments, whose detailed internal structure encodes valuable information about the interactions of high energy quarks and gluons and their confinement into color-neutral hadrons. The flow of energy within jets is characterized by correlation functions of energy flow operators, with the three-point correlator being the first correlator with nontrivial shape dependence, playing a special role in unraveling the dynamics of QCD. In this Letter, we initiate a study of the three-point energy correlator to all orders in the strong coupling constant, in the limit where two of the detectors are squeezed together. We show that, by rotating the two squeezed detectors with respect to the third by an angle $\varphi$, a $\cos (2\varphi )$ dependence arising from the quantum interference between intermediate virtual gluons with $+/-$ helicity is imprinted on the detector. This can be regarded as a double slit experiment performed with jet substructure, and it provides a direct probe of the ultimately quantum nature of the substructure of jets and of transverse spin physics in QCD. To facilitate our all-orders analysis, we adopt the operator product expansion (OPE) for light-ray operators in conformal field theory and develop it in QCD. Our application of the light-ray OPE in real world QCD establishes it as a powerful theoretical tool with broad applications for the study of jet substructure.

Above-threshold ionization spectra from cesium are measured as a function of the carrier-envelope phase (CEP) using laser pulses centered at $3.1\mu \mathrm{m}$ wavelength. The directional asymmetry in the energy spectra of backscattered electrons oscillates three times, rather than once, as the CEP is changed from 0 to $2\pi$. Using the improved strong-field approximation, we show that the unusual behavior arises from the interference of few quantum orbits. We discuss the conditions for observing the high-order CEP dependence, and draw an analogy with time-domain holography with electron wave packets.

We report the observation of quantum interference between electron wave packets launched from the inner-shell $4d$ orbital of the Xe atom. Using pairs of femtosecond radiation wave packets from a synchrotron light source, we obtain time-domain interferograms for the inner-shell excitations. This approach enables the experimental verification and control of the quantum interference between the electron wave packets. Furthermore, the femtosecond Auger decay of the inner-shell excited state is tracked. To the best of our knowledge, this is the first observation of wave packet interference in an atomic inner-shell process, and also the first time-resolved experiment on few-femtosecond Auger decay using a synchrotron light source.

Calculations are presented of vibrational wave packet dynamics in ${\mathrm{H}}_2^{+}$ ions formed by ionization of neutral ${\mathrm{H}}_2$ by a pair of attosecond extreme ultraviolet laser pulses, using time-delayed dissociation of the cation by an ultraviolet probe pulse. The strength of experimentally observable two-level quantum beats as a function of the attosecond two-pulse delay can be related to $\text{ion}+\text{photoelectron}$ entanglement resulting from the ionization process. This conclusion is supported by an evaluation of the purity of the reduced ion and photoelectron density matrices.

We study a bulk fermionic dipolar molecular gas in the quantum degenerate regime confined in a two-dimensional geometry. Using two rotational states of the molecules, we encode a spin $1/2$ degree of freedom. To describe the many-body spin dynamics of the molecules, we derive a long-range interacting $XXZ$ model valid in the regime where motional degrees of freedom are frozen. Because of the spatially extended nature of the harmonic oscillator modes, the interactions in the spin model are very long ranged, and the system behaves close to the collective limit, resulting in robust dynamics and generation of entanglement in the form of spin squeezing even at finite temperature and in the presence of dephasing and chemical reactions. We discuss how the internal state structure can be exploited to realize time reversal and enhanced metrological sensing protocols.

Experimental studies of the simultaneous acceleration of three-charge-state ${}^{129}{\mathrm{Xe}}^{49+,50+,51+}$ beam from 17 to $180\mathrm{MeV}/\mathrm{nucleon}$ in a superconducting linear accelerator are presented. The beam parameters for each individual- and multiple-charge-state beam were measured and compared with the particle tracking simulations. Detailed measurements were performed to characterize the multiple-charge-state beam’s recombination after a second-order achromat and isopath 180° bending system. As a result of the recombination of three charge states in the six-dimensional phase space, the xenon beam intensity was increased by 2.5-fold compared to the single-charge-state beam. The results presented in the Letter fully validate the possibility to produce and utilize high-quality multiple-charge-state heavy-ion beams in a large-scale superconducting linac to increase the available beam power on an isotope production target.

Extracting long-lasting performance from electronic devices and improving their reliability through effective heat management requires good thermal conductors. Taking both three- and four-phonon scattering as well as electron-phonon and isotope scattering into account, we predict that semimetallic $\theta$-phase tantalum nitride ($\theta \text{−}\mathrm{TaN}$) has an ultrahigh thermal conductivity ($\kappa$), of 995 and $\text{820\hspace{0.17em}\hspace{0.17em}}\mathrm{W}{\mathrm{m}}^{-1}{\mathrm{K}}^{-1}$ at room temperature along the $a$ and $c$ axes, respectively. Phonons are found to be the main heat carriers, and the high $\kappa$ hinges on a particular combination of factors: weak electron-phonon scattering, low isotopic mass disorder, and a large frequency gap between acoustic and optical phonon modes that, together with acoustic bunching, impedes three-phonon processes. On the other hand, four-phonon scattering is found to be significant. This study provides new insight into heat conduction in semimetallic solids and extends the search for high-$\kappa$ materials into the realms of semimetals and noncubic crystal structures.

Understanding the activity of large populations of neurons is difficult due to the combinatorial complexity of possible cell-cell interactions. To reduce the complexity, coarse graining had been previously applied to experimental neural recordings, which showed over two decades of apparent scaling in free energy, activity variance, eigenvalue spectra, and correlation time, hinting that the mouse hippocampus operates in a critical regime. We model such data by simulating conditionally independent binary neurons coupled to a small number of long-timescale stochastic fields and then replicating the coarse-graining procedure and analysis. This reproduces the experimentally observed scalings, suggesting that they do not require fine-tuning of internal parameters, but will arise in any system, biological or not, where activity variables are coupled to latent dynamic stimuli. Parameter sweeps for our model suggest that emergence of scaling requires most of the cells in a population to couple to the latent stimuli, predicting that even the celebrated place cells must also respond to nonplace stimuli.

The tensor product postulate of quantum mechanics states that the Hilbert space of a composite system is the tensor product of the components’ Hilbert spaces. All current formalizations of quantum mechanics that do not contain this postulate contain some equivalent postulate or assumption (sometimes hidden). Here we give a natural definition of a composite system as a set containing the component systems and show how one can logically derive the tensor product rule from the state postulate and from the measurement postulate. In other words, our Letter reduces by one the number of postulates necessary to quantum mechanics.

Quantum computation promises intrinsically parallel information processing capacity by harnessing the superposition and entanglement of quantum states. However, it is still challenging to realize universal quantum computation due that the reliability and scalability are limited by unavoidable noises on qubits. Nontrivial topological properties like quantum Hall phases are found capable of offering protection, but require stringent conditions of topological band gaps and broken time-reversal symmetry. Here, we propose and experimentally demonstrate a symmetry-induced error filtering scheme, showing a more general role of geometry in protection mechanism and applications. We encode qubits in a superposition of two spatial modes on a photonic Lieb lattice. The geometric symmetry endows the system with topological properties featuring a flat band touching, leading to distinctive transmission behaviors of $\pi$-phase qubits and 0-phase qubits. The geometry exhibits a significant effect on filtering phase errors, which also enables it to monitor phase deviations in real time. The symmetry-induced error filtering can be a key element for encoding and protecting quantum states, suggesting an emerging field of symmetry-protected universal quantum computation and noisy intermediate-scale quantum technologies.

The transmission of a two-level quantum emitter in its ground state through a graphene nanosheet is investigated. The graphene plasmons (GPs) field distribution, especially the opposite orientations of the vertical electric field components on the two sides of the graphene nanosheet, produces a significant nonadiabatic process during the interaction between the emitter and the localized GPs. By taking into account the counterrotating terms, the excitation of the quantum emitter with simultaneous emission of a GP has a large probability. This happens for emitter speeds of about ${10}^{-4}$ times the speed of light. For accelerated emitters, the GPs exhibit thermal field photon distribution with a high temperature. As a consequence, this study provides a promising platform to observe the dynamical Casimir effect as well as a simulation of the Unruh effect.

Magnetic beads attract each other, forming chains. We push such chains into an inclined Hele-Shaw cell and discover that they spontaneously form self-similar patterns. Depending on the angle of inclination of the cell, two completely different situations emerge; namely, above the static friction angle the patterns resemble the stacking of a rope and below they look similar to a fortress from above. Moreover, locally the first pattern forms a square lattice, while the second pattern exhibits triangular symmetry. For both patterns, the size distributions of enclosed areas follow power laws. We characterize the morphological transition between the two patterns experimentally and numerically and explain the change in polarization as a competition between friction-induced buckling and gravity.