Large transparent touch screens (LTTS) have recently become commercially available. These displays have the potential for engaging Augmented Reality (AR) applications, especially in public and shared spaces. However, the interaction with objects in the real environment behind the display remains challenging: Users must combine pointing and touch input if they want to select objects at varying distances. There is a lot of work on wearable or mobile AR displays, but little on how users interact with LTTS. Our goal is to contribute to a better understanding of natural user interaction for these AR displays. To this end, we developed a prototype and evaluated different pointing techniques for selecting 12 physical targets behind an LTTS, with distances ranging from 6 to 401 cm. We conducted a user study with 16 participants and measured user preferences, performance, and behavior. We analyzed the change in accuracy depending on the target position and the selection technique used. Our findings include: (a) Users naturally align the touch point with their line of sight for targets farther than 36 cm behind the LTTS. (b) This technique provides the lowest angular deviation compared to other techniques. (c) Some user close one eye to improve their performance. Our results help to improve future AR scenarios using LTTS systems.

Giant unilamellar vesicles (GUVs), soft cell-sized compartments formed through the self-assembly of lipid molecules, have long been utilized as model systems and passive carriers in membrane biophysics and biomedical applications. However, their potential as dynamically responsive and motile systems remains largely untapped due to challenges in achieving controlled and sustained motion in soft, deformable structures. Here, an autonomous cell-like microrobot through the emergent self-assembly of GUVs (5-10µm) and silica microparticles (1-3µm) under alternating current electric fields is realized. Self-propulsion arises from asymmetric self-organization of the particles on the vesicle surface, enabling a reversible transformation of the assembly into an active structure. Unlike rigid colloidal systems, GUVs introduce unique features enabled by their soft lipid membranes: shape deformations, membrane tension-dependent motility, and field-triggered live bacteria release via vesicle bursting. Through experiments and simulations, the mechanisms underlying self-assembly and propulsion are investigated, and a dynamic phase diagram is constructed to map the motion regime as a function of field parameters. Finally, it is shown that these self-assembled structures are capable of reconfiguration in response to local constraints in the environment, suggesting potential applications in complex environments and advancing the potential of GUVs toward the rational design of cell-like microrobots or artificial cell systems.

The viscosity of nanoparticle suspensions is always expected to increase with particle concentration. However, a growing body of experiments on suspensions of atomically thin nanomaterials such as graphene contradicts this expectation. Some experiments indicate effective suspension viscosities below that of pure solvent at high shear rates and low solid concentrations, i.e., the intrinsic viscosity is negative. Using molecular dynamics simulations, we investigate the shear viscosity of few-nanometer graphene sheets in water at high Péclet numbers (Pe ≥ 100), for aspect ratios from 4.5 to 12.0. These simulations robustly confirm that the intrinsic viscosity decreases with increasing aspect ratio and becomes negative beyond a threshold ≈5.5, providing a molecular-level confirmation of this behavior in a realistic graphene-water system. Comparison with continuum boundary integral modeling shows quantitative agreement in the dilute regime, confirming the effect is hydrodynamic in origin. We demonstrate that this anomalous behavior originates from hydrodynamic slip at the liquid-solid interface, which suppresses particle rotation and promotes stable alignment with the flow direction, thereby reducing viscous dissipation relative to dissipation in pure solvent. This slip mechanism holds for both fully 3D disc-like and quasi-2D particle geometries explored in the molecular simulations. As the concentration of graphene particles increases in the dilute regime, the viscosity initially decreases, falling below that of pure water. At higher concentrations, however, particle aggregation becomes significant, leading to a rise in viscosity after a minimum is reached. Our work has important implications for the design of lubricants, inks, and nanocomposites with tunable viscosity.

Mixing of different components of the total nuclear spin in the rovibrational states of isolated molecules is extremely weak. It has only been observed in hyperfine spectra for few systems, including S2Cl2, SiF4, PH3, and SF6. We perform variational calculations of nuclear quadrupole interactions in the rotational spectra of S2Cl2 and CH2Cl2 and analyze the effects of breaking the molecular symmetry by isotopic substitution of one of the chlorine atoms. This symmetry breaking significantly enhances the mixing of nuclear spin states and produces a distinct spin polarization pattern with opposite spin orientations on the different isotopes. This enhancement arises as a resonance effect driven jointly by differences in isotopic masses and nuclear quadrupole coupling constants and gives rise to electric and magnetic dipole transitions between states with different relative orientations of the nuclear spin.

Abrikosov vortices, where the superconducting gap is completely suppressed in the core, are dissipative, semi-classical entities that impact applications from high-current-density wires to superconducting quantum devices. In contrast, we present evidence that vortices trapped in granular superconducting films can behave as two-level systems, exhibiting microsecond-range quantum coherence and energy relaxation times that reach fractions of a millisecond. These findings support recent theoretical modeling of superconductors with granularity on the scale of the coherence length as tunnel junction networks, resulting in gapped vortices. Using the tools of circuit quantum electrodynamics, we perform coherent manipulation and quantum non-demolition readout of vortex states in granular aluminum microwave resonators, heralding new directions for quantum information processing, materials characterization, and sensing.