Vortices are topological defects of type-II superconductors in an external magnetic field. In a similar fashion to a quantum anomalous Hall insulator, quantum anomalous vortices (QAV) spontaneously nucleate due to orbital-and-spin exchange interaction between supercurrent and magnetic impurity moment without an external magnetic field. Here, we used scanning superconducting quantum interference device microscopy (sSQUID) to search for its signatures in iron-chalcogenide superconductor Fe(Se,Te). Under zero magnetic field, we found a stochastic distribution of isolated anomalous vortices and antivortices with flux quanta ${\mathrm{\Phi }}_0$. By applying a small local magnetic field under the coil of the nano-SQUID device, we observed hysteretic flipping of the vortices reminiscent of the switching of ferromagnetic domains, suggesting locally broken time-reversal symmetry. We further observed vectorial rotation of a flux line linking a vortex-antivortex pair by manipulating the local field. These unique properties of the anomalous vortices satisfy the defining criteria of QAV. Our observation suggests an emergent quantum phase with spontaneously nucleated vortex-antivortex matter in an iron-based superconductor with nontrivial topological band structure.

The studies of disordered heterogeneous media and galaxy cosmology share a common goal: analyzing the disordered distribution of particles and/or building blocks at microscales to predict physical properties of the medium at macroscales, whether it be a liquid, colloidal suspension, composite material, galaxy cluster, or entire Universe. The theory of disordered heterogeneous media provides an array of theoretical and computational techniques to characterize a wide class of complex material microstructures. In this work, we apply them to describe the disordered distributions of galaxies obtained from recent suites of dark matter simulations. We focus on the determination of lower-order correlation functions, void and particle nearest-neighbor functions, certain cluster statistics, pair-connectedness functions, percolation properties, and a scalar order metric to quantify the degree of order. Compared to analogous homogeneous Poisson and typical disordered systems, the cosmological simulations exhibit enhanced large-scale clustering and longer tails in the void and particle nearest-neighbor functions, due to the presence of quasi-long-range correlations imprinted by early Universe physics, with a minimum particle separation far below the mean nearest-neighbor distance. On large scales, the system appears hyperuniform, as a result of primordial density fluctuations, while on the smallest scales, the system becomes almost antihyperuniform, as evidenced by its number variance. Additionally, via a finite-scaling analysis, we compute the percolation threshold of the galaxy catalogs, finding this to be significantly lower than for Poisson realizations (at reduced density ${\eta }_c=0.25$ in our fiducial analysis compared to ${\eta }_c=0.34$), with strong dependence on the mean density; this is consistent with the observation that the galaxy distribution contains voids of up to 50% larger radius. However, the two sets of simulations appear to share the same fractal dimension on scales much larger than the average intergalaxy separation, implying that they lie in the same universality class. We also show that the distribution of galaxies is a highly correlated disordered system (relative to the uncorrelated Poisson distribution), as measured by the $\tau$ order metric. Finally, we consider the ability of large-scale clustering statistics to constrain cosmological parameters, such as the Universe’s expansion rate, using simulation-based inference. Both the nearest-neighbor distribution and pair-connectedness function (which includes contributions from correlation functions of all order) are found to considerably tighten bounds on the amplitude of quantum-mechanical fluctuations from inflation at a level equivalent to observing 25 times more galaxies. The pair-connectedness function in particular provides a useful alternative to the standard three-particle correlation, since it contains similar large-scale information to the three-point function, can be computed highly efficiently, and can be straightforwardly extended to small scales (though likely requires simulation-based modeling). This work provides the first application of such techniques to cosmology, providing both a novel system to test heterogeneous media descriptors and a tranche of new tools for cosmological analyses. A range of extensions are possible, including implementation on observational data; this will require further study on various observational effects, necessitating high-resolution simulations.

Multipolar spindles are very rare in normal tissues, but they are much more prevalent in many tumors, which might be induced by the mechanical confinements from overcrowding microenvironments in tumors. However, little is known about what the difference is between various forms of mechanical confinements that cells encounter in normal tissues and tumor tissues, and how they affect multipolarity and chromosome segregation fidelity. Here, we use microchannels with different heights and widths to mimic diverse forms and degrees of mechanical constraints within the tissue architecture. We find that multipolar spindles occur frequently under two-wall confinement but that they are rare under four-wall confinement, suggesting that multipolar-spindle assembly depends on the form of the three-dimensional mechanical confinement. We reveal that two-wall confinement leads to an increased fraction of multipolar spindles by pole splitting, while four-wall confinement restrains multipolarity by the enhancement of pole clustering and the inhibition of pole splitting. We further conduct numerical simulations and develop a theoretical model to investigate how mechanical confinement influences pole splitting and clustering. By exploring the energy landscape of pole-pole interactions and pole-cortex interactions and treating pole splitting and clustering as reversible reactions, we demonstrate that mechanical confinement controls cell shape and pole-cortex interactions, which, in turn, change the energy barriers of pole splitting and clustering as well as the probability of multipolar mitosis. Further experiments confirm the theoretical prediction that the pole-cortex interaction determines the probability of the multipolar spindles under various mechanical confinements. Our findings demonstrate the extent to which extracellular microenvironments and tissue architecture can affect complex cellular behaviors, indicating that normal tissue architecture may have the ability to suppress the progress of cancers. Thus, our findings would provide essential cues for cancer therapies targeting the tumor microenvironment.

From fairy circles to patterned ground and columnar joints, natural patterns spontaneously appear in many complex geophysical settings. Here, we investigate the origins of polygonally patterned crusts of salt playa and salt pans. These beautifully regular features, approximately a meter in diameter, are found worldwide and are fundamentally important to the transport of salt and dust in arid regions. We show that they are consistent with the surface expression of buoyancy-driven convection in the porous soil beneath a salt crust. By combining quantitative results from direct field observations, analog experiments, and numerical simulations, we further determine the conditions under which salt polygons should form, as well as how their characteristic size emerges.

The rheology of dense colloidal suspensions, which may undergo discontinuous shear thickening or shear jamming, is particularly difficult to analyze with conventional rheometers. Here, we develop a rheometer adapted to colloidal suspensions: the “capillarytron,” which uses the air-suspension capillary interface to impose particle (or osmotic) pressure during shear. The main virtues of this new device are that (i) it gives direct access to the suspension friction coefficient, (ii) it operates for very dense suspensions up to jamming, and, most importantly, (iii) it decouples the stresses developed within the suspension from the applied shear rate. We can, thus, smoothly move through the different frictional states of the system, precisely in the range of volume fractions where discontinuous shear thickening or shear jamming occur under volume-imposed conditions. Our results obtained with the capillarytron provide the first complete characterization of the dual frictional behavior of a model shear-thickening suspension, in agreement with the recently proposed frictional transition scenario. Based on a new concept in rheometry, the capillarytron unlocks the path to pressure-imposed rheology on colloidal and Brownian suspensions. Moreover, its fine control of the particle pressure via the soft capillary interface opens the possibility to explore the flow of “fragile” particles close to jamming, such as Brownian colloids, active particles, and living cells.

Three key metrics for readout systems in quantum processors are measurement speed, fidelity, and footprint. Fast high-fidelity readout enables midcircuit measurements, a necessary feature for many dynamic algorithms and quantum error correction, while a small footprint facilitates the design of scalable, highly connected architectures with the associated increase in computing performance. Here, we present two complementary demonstrations of fast high-fidelity single-shot readout of spins in silicon quantum dots using a compact, dispersive charge sensor: a radio-frequency single-electron box. The sensor, despite requiring fewer electrodes than conventional detectors, performs at the state of the art achieving spin readout fidelity of 99.2% in less than $6\mathrm{\mu }\mathrm{s}$ fitted from a physical model. We demonstrate that low-loss high-impedance resonators, highly coupled to the sensing dot, in conjunction with Josephson parametric amplification are instrumental in achieving optimal performance. We quantify the benefit of Pauli spin blockade over spin-dependent tunneling to a reservoir, as the spin-to-charge conversion mechanism in these readout schemes. Our results place dispersive charge sensing at the forefront of readout methodologies for scalable semiconductor spin-based quantum processors.

Solid-liquid interfaces display a wealth of emerging phenomena at nanometer scales, which are at the root of their technological applications. While the interfacial structure and chemistry have been intensively explored, the potential coupling between liquid flows and the solid’s electronic degrees of freedom has been broadly overlooked up till now. Despite several reports of electronic currents induced by liquids flowing in various carbon nanostructures, the mechanisms at stake remain controversial. Here, we unveil the molecular mechanisms of interfacial liquid-electron coupling by investigating flow-induced current generation at the nanoscale. We use a tuning fork atomic force microscope to deposit and displace a micrometric liquid droplet on a multilayer graphene sample, and observe an electronic current induced by the droplet displacement. The measured current is several orders of magnitude larger than previously reported for water on carbon, and further boosted by the presence of surface wrinkles on the carbon surface. Our results point to a peculiar momentum transfer mechanism between the fluid molecules and graphene charge carriers, mediated mainly by the solid’s phonon excitations. These findings open new avenues for active control of nanoscale liquid flows through the solid walls’ electronic degrees of freedom.

Attractor networks are an influential theory for memory storage in brain systems. This theory has recently been challenged by the observation of strong temporal variability in neuronal recordings during memory tasks. In this work, we study a sparsely connected attractor network where memories are learned according to a Hebbian synaptic plasticity rule. After recapitulating known results for the continuous, sparsely connected Hopfield model, we investigate a model in which new memories are learned continuously and old memories are forgotten, using an online synaptic plasticity rule. We show that for a forgetting timescale that optimizes storage capacity, the qualitative features of the network’s memory retrieval dynamics are age dependent: most recent memories are retrieved as fixed-point attractors while older memories are retrieved as chaotic attractors characterized by strong heterogeneity and temporal fluctuations. Therefore, fixed-point and chaotic attractors coexist in the network phase space. The network presents a continuum of statistically distinguishable memory states, where chaotic fluctuations appear abruptly above a critical age and then increase gradually until the memory disappears. We develop a dynamical mean field theory to analyze the age-dependent dynamics and compare the theory with simulations of large networks. We compute the optimal forgetting timescale for which the number of stored memories is maximized. We found that the maximum age at which memories can be retrieved is given by an instability at which old memories destabilize and the network converges instead to a more recent one. Our numerical simulations show that a high degree of sparsity is necessary for the dynamical mean field theory to accurately predict the network capacity. To test the robustness and biological plausibility of our results, we study numerically the dynamics of a network with learning rules and transfer function inferred from in vivo data in the online learning scenario. We found that all aspects of the network’s dynamics characterized analytically in the simpler model also hold in this model. These results are highly robust to noise. Finally, our theory provides specific predictions for delay response tasks with aging memoranda. In particular, it predicts a higher degree of temporal fluctuations in retrieval states associated with older memories, and it also predicts fluctuations should be faster in older memories. Overall, our theory of attractor networks that continuously learn new information at the price of forgetting old memories can account for the observed diversity of retrieval states in the cortex, and in particular, the strong temporal fluctuations of cortical activity.

Analog quantum simulators, which efficiently represent model systems, have the potential to provide new insight toward naturally occurring phenomena beyond the capabilities of classical computers. Incorporating dissipation as a resource unlocks a wider range of out-of-equilibrium processes such as chemical reactions. Here, we operate a hybrid qubit-oscillator circuit quantum electrodynamics simulator and model nonadiabatic molecular dynamics through a conical intersection. We identify dephasing of the electronic qubit as the mechanism that drives wave-packet branching when the corresponding oscillator undergoes large amplitude motion. Furthermore, we directly observe enhanced branching when the wave-packet passes through the conical intersection. Thus, the forces that influence a chemical reaction can be viewed from the perspective of measurement backaction in quantum mechanics—there is an effective measurement-induced dephasing rate that depends on the position of the wave packet relative to the conical intersection. Our results set the groundwork for more complex simulations of chemical dynamics using quantum simulators, offering deeper insight into the role of dissipation in determining macroscopic quantities of interest such as the quantum yield of a chemical reaction.

The distant projection of high-peak and average-power laser beams in the atmosphere is a long-standing goal with a wide range of applications. Our early proof-of-principle experiments [Phys. Rev. X 4, 011027 (2014)] presented one solution to this problem, employing the energy deposition of femtosecond filaments in air to sculpt millisecond-lifetime sub-meter-length air waveguides. Here, we demonstrate air waveguiding at the 50-m scale, $60\times \text{longer}$, making many practical applications now possible. We employ a new method for filament energy deposition: multifilamentation of Laguerre-Gaussian ${\mathrm{LG}}_{01}$ “donut” modes. We first investigate the detailed physics of this scheme over a shorter 8-m in-lab propagation range corresponding to 13 Rayleigh lengths of the guided pulse. We then use these results to demonstrate optical guiding over 45 m in the hallway adjacent to the lab, corresponding to 70 Rayleigh lengths. Injection of a continuous-wave probe beam into these waveguides demonstrates very long lifetimes of tens of milliseconds.

Because electrons and ions form a coupled system, it is a priori clear that the dynamics of the lattice should reflect symmetry breaking within the electronic degrees of freedom. Recently, this has been clearly evidenced for the case of time-reversal and mirror symmetry breaking by observations of a large phononic thermal Hall effect in many strongly correlated electronic materials. However, the mechanism by which time-reversal breaking and chirality is communicated to the lattice is far from evident. In this paper, we discuss how this occurs via many-body scattering of phonons by collective modes: a consequence of non-Gaussian correlations of the latter modes. We derive fundamental new results for such skew (i.e., chiral) scattering and the consequent thermal Hall conductivity. We emphasize that these results apply to any collective variables in any phase of matter: electronic, magnetic, or neither; highly fluctuating and correlated, or not. As a proof of principle, we compute general formulas for the above quantities for ordered antiferromagnets. From the latter, we obtain the scaling behavior of the phonon thermal Hall effect in clean antiferromagnets. The calculations show several different regimes and give quantitative estimates of similar order to that seen in recent experiments.

Exotic magnetic textures emerging from the subtle interplay between thermodynamic and topological fluctuation have attracted intense interest due to their potential applications in spintronic devices. Recent advances in electron microscopy enable the imaging of random photogenerated individual skyrmions. However, their deterministic and dynamical manipulation is hampered by the chaotic nature of such fluctuations and the intrinsically irreversible switching between different minima in the magnetic energy landscape. Here, we demonstrate a method to coherently control the rotation of a skyrmion crystal by discrete amounts at speeds which are much faster than previously observed. By employing circularly polarized femtosecond laser pulses with an energy below the band gap of the Mott insulator ${\mathrm{Cu}}_2{\mathrm{OSeO}}_3$, we excite a collective magnon mode via the inverse Faraday effect. This triggers coherent magnetic oscillations that directly control the rotation of a skyrmion crystal imaged by cryo-Lorentz transmission electron microscopy. The manipulation of topological order via ultrafast laser pulses shown here can be used to engineer fast spin-based logical devices.

A primary requirement for a robust and unconditionally secure quantum network is the establishment of quantum nonlocal correlations over a realistic channel. While loophole-free tests of Bell nonlocality allow for entanglement certification in such a device-independent setting, they are extremely sensitive to loss and noise, which naturally arise in any practical communication scenario. Quantum steering relaxes the strict technological constraints of Bell nonlocality by reframing it in an asymmetric manner, with a trusted party only on one side. However, tests of quantum steering still require either extremely high-quality entanglement or very low loss. Here we introduce a test of quantum steering that harnesses the advantages of high-dimensional entanglement to be simultaneously noise robust and loss tolerant. Despite being constructed for qudits, our steering test is designed for single-detector measurements and is able to close the fair-sampling loophole in a time-efficient manner. We showcase the improvements over qubit-based systems by experimentally demonstrating quantum steering in up to 53 dimensions, free of the fair-sampling loophole, through simultaneous loss and noise conditions corresponding to 14.2-dB loss equivalent to 79 km of telecommunication fiber, and 36% of white noise. We go on to show how the use of high dimensions counterintuitively leads to a dramatic reduction in total measurement time, enabling a quantum steering violation almost 2 orders of magnitude faster obtained by simply doubling the Hilbert space dimension. Our work conclusively demonstrates the significant resource advantages that high-dimensional entanglement provides for quantum steering in terms of loss, noise, and measurement time, and opens the door toward practical quantum networks with the ultimate form of security.

Phononic frequency combs have attracted increasing attention both as a qualitatively new type of nonlinear phenomena in vibrational systems and from the point of view of applications. It is commonly believed that at least two modes must be involved in generating a comb. We demonstrate that a comb can be generated by a single nanomechanical mode driven by a resonant monochromatic drive. The comb emerges where the drive is still weak, so the anharmonic part of the mode potential energy remains small. We relate the experimental observation to a negative nonlinear friction induced by the resonant drive, which makes the vibrations at the drive frequency unstable. We directly map the measured trajectories of the emerging oscillations in the rotating frame and show how these oscillations lead to the frequency comb in the laboratory frame. The results go beyond nanomechanics and suggest a qualitatively new approach to generating tunable frequency combs in single-mode vibrational systems. They demonstrate new sides of the interplay of conservative and dissipative nonlinearities in driven systems.

We present experimental results on a plasma wakefield accelerator (PWFA) driven by high-current electron beams from a laser wakefield accelerator (LWFA). In this staged setup stable and high-quality (low-divergence and low energy spread) electron beams are generated at an optically generated hydrodynamic shock in the PWFA. The energy stability of the beams produced by that arrangement in the PWFA stage is comparable to both single-stage laser accelerators and plasma wakefield accelerators driven by conventional accelerators. Simulations support that the intrinsic insensitivity of PWFAs to driver energy fluctuations can be exploited to overcome stability limitations of state-of-the-art laser wakefield accelerators when adding a PWFA stage. Furthermore, we demonstrate the generation of electron bunches with energy spread and divergence superior to single-stage LWFAs, resulting in bunches with dense phase space and an angular-spectral charge density beyond the initial drive beam parameters. These results unambiguously show that staged LWFA-PWFA can help to tailor the electron-beam quality for certain applications and to reduce the influence of fluctuating laser drivers on the electron-beam stability. This encourages further development of this new class of staged wakefield acceleration as a viable scheme toward compact, high-quality electron beam sources.

As in conventional computing, memories for quantum information benefit from high storage density and, crucially, random access, or the ability to read from or write to an arbitrarily chosen register. However, achieving such random access with quantum memories in a dense, hardware-efficient manner remains a challenge. Here we introduce a protocol using chirped pulses to encode qubits within an ensemble of quantum two-level systems, offering both random access and naturally supporting dynamical decoupling to enhance the memory lifetime. We demonstrate the protocol in the microwave regime using donor spins in silicon coupled to a superconducting cavity, storing up to four weak, coherent microwave pulses in distinct memory modes and retrieving them on demand up to 2 ms later. This approach offers the potential for microwave random access quantum memories with lifetimes exceeding seconds, while the chirped pulse phase encoding could also be applied in the optical regime to enhance quantum repeaters and networks.

We present a novel framework for the equation of state of dense and hot quantum chromodynamics (QCD), which focuses on the region of the phase diagram relevant for neutron star mergers and core-collapse supernovae. The model combines predictions from the gauge/gravity duality with input from lattice field theory, QCD perturbation theory, chiral effective theory, and statistical modeling. It is therefore, by construction, in good agreement with theoretical constraints both at low and high densities and temperatures. The main ingredients of our setup are the nonperturbative V-QCD model based on the gauge/gravity duality, a van der Waals model for nucleon liquid, and the DD2 version of the Hempel-Schaffner-Bielich statistical model of nuclear matter. By consistently combining these models, we also obtain a description for the nuclear to quark matter phase transition and its critical end point. The parameter dependence of the model is represented by three (soft, intermediate, and stiff) variants of the equation of state, all of which agree with observational constraints from neutron stars and their mergers. We discuss resulting constraints for the equation of state, predictions for neutron stars, and the location of the critical point.

The realization of a scalable architecture for quantum information processing is a major challenge for quantum science. A promising approach is based on emitters in nanostructures that are coupled by light. Here, we show that erbium dopants can be reproducibly integrated at well-defined lattice sites by implantation into pure silicon. We thus achieve a narrow inhomogeneous broadening, less than 1 GHz, strong optical transitions, and an outstanding optical coherence even at temperatures of 8 K, with an upper bound to the homogeneous linewidth of around 10 kHz. Our study thus introduces a promising materials platform for the implementation of on-chip quantum memories, microwave-to-optical conversion, and distributed quantum information processing.

Relativity opens the door to a counterintuitive fact: A state can be stable to perturbations in one frame of reference and unstable in another one. For this reason, the job of testing the stability of states that are not Lorentz invariant can be very cumbersome. We show that two observers can disagree on whether a state is stable or unstable only if the perturbations can exit the light cone. Furthermore, we show that, if a perturbation exits the light cone and its intensity changes with time due to dissipation, then there are always two observers that disagree on the stability of the state. Hence, “stability” is a Lorentz-invariant property of dissipative theories if and only if the principle of causality is respected. We present 14 applications to physical problems from all areas of relativistic physics ranging from theory to simulation.

Interfacing electrons and light enables ultrafast electron microscopy and quantum control of electrons, as well as new optical elements for high-sensitivity imaging. Here, we demonstrate for the first time programmable transverse electron-beam shaping in free space based on ponderomotive potentials from short intense laser pulses. We can realize both convex and concave electron lenses with a focal length of a few millimeters, comparable to those in state-of-the-art electron microscopes. We further show that we can realize almost arbitrary deflection patterns by shaping the ponderomotive potentials using a spatial light modulator. Our modulator is lossless and programmable, has unity fill factor, and could pave the way to electron wave-front shaping with hundreds of individually addressable pixels.