Recent experiments with degenerate molecular gases dressed by elliptically polarized microwave fields have enabled new control of dipolar interactions via engineered anisotropy. We reveal a symmetry structure of the dipolar interaction that generates degeneracies among the interaction parameters, enabling a classification of spatial symmetries and equilibrium shapes of the gases. Exploiting these symmetries, we analyze solutions including beyond-mean-field quantum fluctuations in the dilute gas regime and develop a complementary variational theory. We map out the phase diagram of self-bound droplets and characterize their widths, energies, and densities.

A prediction makes a claim about a system's future given knowledge of its past. A retrodiction makes a claim about its past given knowledge of its future. The bidirectional machine is an ambidextrous hidden Markov chain that does both optimally by making explicit in its state structure all statistical correlations in a stochastic process. We introduce an informational taxonomy to profile these correlations via a suite of multivariate information measures. While prior results laid out the different kinds of information contained in isolated measurements, the associated informations were challenging to calculate explicitly. Overcoming this via bidirectional machine states, we expand that analysis to prediction and retrodiction. The result highlights fourteen interpretable and calculable measures that characterize a process's informational structure. In addition, we introduce a labeling and indexing scheme that systematizes information-theoretic analyses of complex multivariate systems. Operationalizing this, we provide algorithms to directly calculate all of these quantities in closed form for finitely modeled processes.

Anisotropic rodlike particles form liquid crystalline phases with varying degrees of orientational and translational order. When confined geometrically, these phases can give rise to topological defects, which can be selected and controlled by tuning how the rods align near boundaries, known as anchoring. While anchoring in molecular liquid crystals can be controlled through surface functionalization, this approach is not easily applicable to microscale colloidal systems, which have so far been limited to planar anchoring. Here, using particle-based simulations, Landau–de Gennes theory, and experiments on colloidal rods, we demonstrate that topographical patterning of the boundary can effectively control the anchoring type and, in turn, the defect state in two-dimensional confined nematics. Building on this, we numerically predict that dynamically shape shifting the boundaries can transform and transport topological defects.

Understanding how cells sense mechanical cues and regulate migration is crucial in the development, fibrosis, and oncogenesis processes. However, a comprehensive physical picture of cell migration remains lacking, given the diverse environmental properties and cell physiologies. Here, we generalize the motor-clutch model to the whole-cell level and systematically investigate the effects of substrate stiffness, friction, and actin polymerization speed on cell migration. We unveil three distinct migration modes: gripping, slipping, and stick-slip. Notably, stiffness sensing occurs exclusively in the stick-slip mode, which requires a low substrate stiffness and a minimum actin polymerization speed as necessary conditions. Intriguingly, the optimal substrate stiffness that maximizes the migration speed is inversely proportional to the actin polymerization speed. Moreover, the maximal speed only depends on the nature of the clutch molecules, independent of substrate properties. We reveal the boundary criteria among the three migration modes and demonstrate that fast- and slow-migrating cells can coexist in an isogenic cell population without the need for biochemical feedback loops.

We report a joint experimental and theoretical study of core ionization of fenchone enantiomers at photon energies in the range 294.9–306.9 eV. Our experimental method enables the measurement of photoelectron momentum distributions with full $4\pi$ solid-angle coverage in the laboratory frame, yielding photon-energy-resolved dichroic and anisotropy parameters for photoelectrons emitted from C $1s$ ($\mathrm{C}\text{=}\mathrm{O}$ and $\mathrm{C}–{\mathrm{H}}_n$) orbitals. Our experimental results are supported by ab initio electronic-structure calculations and agree fairly well with values available in the literature. Our findings demonstrate that core-level photoelectron circular dichroism is highly sensitive to both the localization of the emitting orbital and the treatment of background contributions, providing a solid basis for future studies of complex chiral molecules.

We present an approach for generating collider-quality electron bunches using a plasma photoinjector. The approach leverages recently developed techniques for the spatiotemporal control of laser pulses to produce a moving ionization front in a nonlinear plasma wave. The moving ionization front generates an electron bunch with a current profile that balances the longitudinal electric field of an electron beam-driven plasma wave, creating a uniform accelerating field across the bunch. Particle-in-cell (PIC) simulations of the ionization stage show the formation of an electron bunch with 220 pC charge and low emittance (${\varepsilon }_x=171$ nm rad, ${\varepsilon }_y=76$ nm rad). Quasistatic PIC simulations of the acceleration stage show that the bunch is efficiently accelerated to 24 GeV over 2 m with a final energy spread of less than 1% and emittances of ${\varepsilon }_x=189$ nm rad and ${\varepsilon }_y=80$ nm rad. This high-quality electron bunch meets the requirements outlined by the Snowmass process for intermediate-energy colliders and compares favorably to the beam quality of proposed and existing accelerator facilities. The results establish the feasibility of plasma photoinjectors for future collider applications making a significant step toward the realization of high-luminosity, compact accelerators for particle physics research.

We present a further investigation on the optical nonreciprocity based on four-wave mixing (FWM) by leveraging coherently driven cold atoms, as a beneficial supplement to the usual cavity-waveguide solution in virtue of the on-demand tunability and broadband advantage. We consider two parameter regimes unexplored yet, where the probe and coupling fields are set with vanishing or large detunings while the dressing field is kept on resonance. Numerical results reveal that the forward (backward) probe exhibits a high transmittance (is strongly absorbed) in the resonant regime, but may be largely converted into an FWM field (propagate almost freely) in the far-detuned regime. The optimization of such a reversible unidirectional transmission featured by large isolation ratios and low insertion losses can be attained only when the coupling and dressing fields fulfill different scaling relations in amplitude, which has been well explained via analytical results. It is also viable to achieve reversible unidirectional transmission for a probe field of fixed large detunings by simply tuning the coupling field in a wide spectral range. Our findings provide additional insights into the FWM-based optical nonreciprocity and may enable more powerful unidirectional devices in quantum networks.

We investigate directional asymmetry in strong-field ionization driven by a few-cycle near-infrared laser pulse assisted by a time-delayed terahertz (THz) pulse. Within the strong-field approximation, we show that the relative delay between the laser and THz pulses provides an efficient control parameter for steering photoelectron emission along the laser polarization axis. Energy-resolved photoelectron spectra, momentum distributions, and asymmetry parameter demonstrate a pronounced and tunable left-right asymmetry for both direct and rescattered electrons, governed by the value of the THz vector potential during the ionization window. This control is significantly stronger than that achievable by varying the carrier-envelope phase of the laser pulse alone and remains robust with respect to variations of the THz-pulse parameters and focal averaging. Our results build upon the theoretical concept introduced earlier [Milošević, Opt. Lett. 47, 1669 (2022)], whose predictions were subsequently confirmed by the experiment [Mitrofanov et al., Opt. Lett. 50, 6626 (2025)], establishing THz-assisted strong-field ionization as a reliable and experimentally validated approach for controlling photoelectron emission on ultrafast timescales.

The relativistic momentum equation of a collisionless plasma is reformulated to describe the time evolution of canonical vorticity. Compared to the nonrelativistic counterpart, an additional source term for canonical vorticity is identified, which embodies the misalignment between the fluid momentum and fluid velocity gradients. This kineclinic term breaks the frozen-in condition of canonical vorticity, thereby enabling the generation or dissipation of magnetic fields and vorticity. We verify the role of this effect through particle-in-cell simulations of a kineclinic flow. Kineclinicity is generically expected in relativistic plasma kinetic plasmas lacking a functional relationship between fluid momentum and fluid velocity.

We experimentally demonstrate the decomposition of heat dissipation during free-energy generation in a nanometer-scale dot transitioning to a nonequilibrium steady state via single-electron counting statistics. An alternating-current signal driving a reservoir that injects multiple electrons into the dot makes it nonequilibrium, leading to free-energy generation, heat dissipation, and Shannon-entropy production. By analyzing the time-domain probability distributions of multielectron states of the dot, we quantitatively decompose the heat dissipation into housekeeping and excess heats, thereby revealing their direct correlation with free-energy generation. This correlation suggests that the ratio of the generated free energy to the work applied to the dot can potentially reach 0.5 under far-from-equilibrium conditions induced by a large signal, while an efficiency of 0.25 was experimentally achieved. These results establish a quantitative link between decomposed heat dissipation and free-energy generation in a multielectron stochastic system, providing a thermodynamic framework for nonequilibrium electronic devices.

Generalized parity measurements are instrumental for the preparation of nontrivial quantum states and the detection of errors in error-correction codes. However, realizing such measurements in current experimental platforms becomes prohibitively difficult with growing system size. Here, using algorithmic methods of quantum signal processing, we detail a simple and efficient control protocol for implementing generalized parity measurements. Crucially, our measurement protocol does not depend on the size of the system and implements the desired measurement in constant time. We benchmark the performance of the proposed measurement protocol in preparing large multicomponent cat states on superconducting circuit quantum electrodynamics platforms. We show that a 20-component cat state with 400 photons can be prepared with success probability $>2\%$ and fidelity $\approx 90\%$ limited by the cavity decay rate and higher-order qubit-cavity coupling. Our results demonstrate the feasibility of generalized parity measurements in current bosonic and spin systems, paving the way to improvements in state-preparation and error-correction capabilities.

We introduce a quantum algorithm for computing the Ollivier-Ricci curvature, a discrete analog of the Ricci curvature defined via optimal transport on graphs and general metric spaces. This curvature has seen applications ranging from signaling fragility in financial networks to serving as basic quantities in combinatorial quantum gravity. For inputs given as a point cloud with pairwise distances, we show that our algorithm can achieve an exponential speedup over the best-known classical methods for two particular classes of problems. Our work is another step toward quantum algorithms for geometrical problems that are capable of delivering practical value while also informing fundamental theory.

Fighting against noise is crucial for Noisy Intermediate Scale Quantum (NISQ) devices to demonstrate practical quantum applications. In this work, we give a paradigm of quantum error mitigation based on the vectorization of density matrices for variational quantum algorithms. Different from the ideas of existing quantum error mitigation methods that try to distill noiseless information from noisy quantum states, our proposal directly changes the way of encoding information and maps the density matrices of noisy quantum states to noiseless virtual pure states, which is realized by an NISQ-friendly measurement protocol and a classical postprocessing procedure. Our protocol requires no knowledge of the noise model, no ability to tune the noise strength, and no ancilla qubits for complicated controlled unitaries. Under our encoding, NISQ devices are always preparing virtual pure quantum states that are highly desired resources for variational quantum algorithms to have good performance in many tasks. We show how this protocol can be well fitted into variational quantum algorithms. We give several concrete ansatz constructions that are suitable for our proposal and do theoretical analysis on the sampling complexity, the expressibility, and the trainability. We also give a discussion on how this protocol is influenced by large noise and how it can be well combined with other quantum error mitigation protocols. The effectiveness of our proposal is demonstrated by various numerical experiments.

We investigate the Reynolds number effect on the dynamical state of a turbulent channel flow by means of orbital-instability-based forecasting method (OIFM) and ordinal partition transition network (OPTN). In the near-wall region, i.e., viscous sublayer and buffer layer, the coexistence of streaky structures with a spanwise spacing of about 100 wall units and large-scale structures with a spanwise spacing on the order of channel half-width decreases the predictive accuracy of streamwise velocity and increases the randomness of streamwise velocity. The low-dimensional chaotic state of streamwise velocity persists in the near-wall region regardless of the friction Reynolds number. In the far-wall region, the high-dimensional chaotic state of streamwise velocity emerges at low friction Reynolds numbers owing to the obvious low-Reynolds-number effect, whereas the low-dimensional chaotic state of streamwise velocity emerges at high friction Reynolds numbers owing to the formation of streamwise and spanwise large-scale structures, i.e., the large-scale motions. The chaotic state of the streamwise velocity at high friction Reynolds numbers is strongly associated with hierarchical structures. The formation of hierarchical structures can be clearly identified at high friction Reynolds numbers through the analyses of the premultiplied streamwise Reynolds stress spectrum and the instantaneous streamwise velocity fluctuations in the $z–y$ plane, whereas it is hardly observed at low friction Reynolds numbers. The results of this study demonstrate that the OIFM and OPTN have high capabilities of elucidating the dynamics in turbulent flows and predicting their behavior.

Using time-dependent density functional theory, we study how density and size of impurities govern dissipation of persistent currents of fermionic superfluid rings in the Bardeen-Cooper-Schrieffer regime. The critical winding number for vortex emission increases with impurity density, but this enhancement is impurity size dependent and capped by the pair-breaking threshold. Below this vortex-emission threshold, the winding number remains constant while flow energy dissipates through impurity-enhanced pair breaking. Above the threshold, vortex-impurity interactions produce distinct mobility regimes—deflected trajectories, individual pinning, collective pinning, and intersite hopping, controlled by the impurity size and density, which determine the dominant dissipation channel. These findings provide design principles for ultracold-atom experiments and insights into vortex-pinning dynamics in neutron-star crusts and superconductors.

Topological phenomena in quantum critical systems have recently attracted growing attention, as they go beyond the traditional paradigms of condensed matter and statistical physics. However, a general framework for identifying such nontrivial phenomena, particularly in higher-dimensional systems, remains insufficiently explored. In this work, we propose a universal fingerprint for detecting nontrivial topology in critical free-fermion systems protected by global on-site symmetries. Specifically, we analytically establish an exact relation between the bulk entanglement spectrum and the boundary energy spectrum at topological criticality in arbitrary dimensions, demonstrating that the degeneracy of edge modes can be extracted from the bulk entanglement spectrum. These findings, further supported by numerical simulations of lattice models, provide a universal fingerprint for identifying nontrivial topology in critical free-fermion systems.