Flexible Nanogenerators Based on Enhanced Flexoelectricity in Mn3O4 Membranes

Atomically thin, few-layered membranes of oxides show unique physical and chemical properties compared to their bulk forms. Manganese oxide (Mn3O4) membranes are exfoliated from the naturally occurring mineral Hausmannite and used to make flexible, high-performance nanogenerators (NGs). An enhanced power density in the membrane NG is observed with the best-performing device showing a power density of 7.99 mW m-2 compared to 1.04 µW m-2 in bulk Mn3O4. A sensitivity of 108 mV kPa-1 for applied forces <10 N in the membrane NG is observed. The improved performance of these NGs is attributed to enhanced flexoelectric response in a few layers of Mn3O4. Using first-principles calculations, the flexoelectric coefficients of monolayer and bilayer Mn3O4 are found to be 50-100 times larger than other 2D transition metal dichalcogenides (TMDCs). Using a model based on classical beam theory, an increasing activation of the bending mode with decreasing thickness of the oxide membranes is observed, which in turn leads to a large flexoelectric response. As a proof-of-concept, flexible NGs using exfoliated Mn3O4 membranes are made and used in self-powered paper-based devices. This research paves the way for the exploration of few-layered membranes of other centrosymmetric oxides for application as energy harvesters.

Predicting quantum emitter fluctuations with time-series forecasting models

2D materials have important fundamental properties allowing for their use in many potential applications, including quantum computing. Various Van der Waals materials, including Tungsten disulfide (WS2), have been employed to showcase attractive device applications such as light emitting diodes, lasers and optical modulators. To maximize the utility and value of integrated quantum photonics, the wavelength, polarization and intensity of the photons from a quantum emission (QE) must be stable. However, random variation of emission energy, caused by the inhomogeneity in the local environment, is a major challenge for all solid-state single photon emitters. In this work, we assess the random nature of the quantum fluctuations, and we present time series forecasting deep learning models to analyse and predict QE fluctuations for the first time. Our trained models can roughly follow the actual trend of the data and, under certain data processing conditions, can predict peaks and dips of the fluctuations. The ability to anticipate these fluctuations will allow physicists to harness quantum fluctuation characteristics to develop novel scientific advances in quantum computing that will greatly benefit quantum technologies.

Robust Classical and Quantum Polarimetry with a Single Nanostructured Metagrating

We formulate a new conceptual approach for one-shot complete polarization state measurement with nanostructured metasurfaces applicable to classical light and multiphoton quantum states by drawing on the principles of generalized quantum measurements based on positive operator-valued measures. Accurate polarization reconstruction from a combination of photon counts or correlations from several diffraction orders is robust with respect to even strong fabrication inaccuracies, requiring only a single classical calibration of the metasurface transmission. Furthermore, this approach operates with a single metagrating without interleaving, allowing for a reduction in metasurface size while preserving high transmission efficiency and output beam quality. We theoretically obtained original metasurface designs, fabricated the metasurface from amorphous silicon nanostructures deposited on glass, and experimentally confirmed accurate polarization reconstruction of laser beams. We also anticipate robust operation under changes in environmental conditions, opening new possibilities for space-based imaging and satellite optics.

Tunable Single-Photon Emission with Wafer-Scale Plasmonic Array

Bright, scalable, and deterministic single-photon emission (SPE) is essential for quantum optics, nanophotonics, and optical information systems. Recently, SPE from hexagonal boron nitride (h-BN) has attracted intense interest because it is optically active and stable at room temperature. Here, we demonstrate a tunable quantum emitter array in h-BN at room temperature by integrating a wafer-scale plasmonic array. The transient voltage electrophoretic deposition (EPD) reaction is developed to effectively enhance the filling of single-crystal nanometals in the designed patterns without aggregation, which ensures the fabricated array for tunable performances of these single-photon emitters. An enhancement of ∼500% of the SPE intensity of the h-BN emitter array is observed with a radiative quantum efficiency of up to 20% and a saturated count rate of more than 4.5 × 106 counts/s. These results suggest the integrated h-BN-plasmonic array as a promising platform for scalable and controllable SPE photonics at room temperature.

Analysis of collision avoidance in honeybee flight

Insects are excellent at flying in dense vegetation and navigating through other complex spatial environments. This study investigates the strategies used by honeybees (Apis mellifera) to avoid collisions with an obstacle encountered frontally during flight. Bees were trained to fly through a tunnel that contained a solitary vertically oriented cylindrical obstacle placed along the midline. Flight trajectories of bees were recorded for six conditions in which the diameter of the obstructing cylinder was systematically varied from 25 mm to 160 mm. Analysis of salient events during the bees' flight, such as the deceleration before the obstacle, and the initiation of the deviation in flight path to avoid collisions, revealed a strategy for obstacle avoidance that is based on the relative retinal expansion velocity generated by the obstacle when the bee is on a collision course. We find that a quantitative model, featuring a controller that extracts specific visual cues from the frontal visual field, provides an accurate characterization of the geometry and the dynamics of the manoeuvres adopted by honeybees to avoid collisions. This study paves the way for the design of unmanned aerial systems, by identifying the visual cues that are used by honeybees for performing robust obstacle avoidance flight.

Synergistic Inclusion Effects of Hard Magnetic Nanorods on the Magnetomechanical Actuation of Soft Magnetic Microsphere-Based Polymer Composites

The magnetomechanical actuation of micropillars is developed for the contactless manipulation of miniaturized actuators and microtextured surfaces. Anisotropic geometry of micropillars can significantly enhance the magnetic actuation compared with their isotropic counterparts by directional stress distributions. However, this strategy is not viable for triangular micropillars owing to insufficient anisotropy. In this study, a significant improvement in the magnetic actuation of triangular micropillars using composite magnetic particles is reported. A minute and optimal amount of hard magnetic gamma-ferrite nanorods are hybridized with soft magnetic iron microspheres to generate synergistic effects of magnetic coupling and percolation phenomenon on the magnetic actuation of polymer composites. The addition of 1 wt% face-centered cubic-phased gamma-ferrite nanorods suppresses the magnetic coupling interference of body-centered cubic-phased iron microspheres. Furthermore, the nanorods reduce the percolation threshold by participating in the percolation of the microspheres. A systematic compositional study on the magnetization and magnetorheological properties reveals that the coupling effect dominates the percolation effect at a low magnetic field, whereas the percolation effect governs the magnetic actuation at a high magnetic field. This hybrid approach can help in designing material constituents for effective magnetic actuators and robotic systems that can sensitively respond to an external magnetic field.

Programming Anisotropic Functionality of 3D Microdenticles by Staggered-Overlapped and Multilayered Microarchitectures

Natural sharkskin features staggered-overlapped and multilayered architectures of riblet-textured anisotropic microdenticles, exhibiting drag reduction and providing a flexible yet strong armor. However, the artificial fabrication of three-dimensional (3D) sharkskin with these unique functionalities and mechanical integrity is a challenge using conventional techniques. In this study, it is reported on the facile microfabrication of multilayered 3D sharkskin through the magnetic actuation of polymeric composites and subsequent chemical shape fixation by casting thin polymeric films. The fabricated hydrophobic sharkskin, with geometric symmetry breaking, achieves anisotropic drag reduction in frontal and backward flow directions against the riblet-textured microdenticles. For mechanical integrity, hard-on-soft multilayered mechanical properties are realized by coating the polymeric sharkskin with thin layers of zinc oxide and platinum, which have higher hardness and recovery behaviors than the polymer. This multilayered hard-on-soft sharkskin exhibits friction anisotropy, mechanical robustness, and structural recovery. Furthermore, coating the MXene nanosheets provides the fabricated sharkskin with a low electrical resistance of ≈5.3 Ω, which leads to high Joule heating (≈229.9 °C at 2.75 V). The proposed magnetomechanical actuation-assisted microfabrication strategy is expected to facilitate the development of devices requiring multifunctional microtextures.

Computational analysis and experimental verification of donor-acceptor behaviour of berberine, and its co-oligomers and co-polymers with ethylenedıoxythıophene

The donor-acceptor (D-A) type of conjugated polymers has emerged as the paradigm of the third generation of electronically conducting polymers demonstrating improved infrared activity and intrinsic electronic conductivity. Judicious selection of donor (D) and acceptor (A) monomers for copolymerization can further fine-tune these properties. Notably, for such refinement, natural compounds provide many conjugated molecules with various functional groups. Berberine cation (Ber+) found in Coscinium fenestratum has extensive conjugation and contains both an electron deficient isoquinolium A moiety and electron-rich D-type methylenedioxy and methoxy groups. The incorporation of natural products in electronic materials is a novel area of research which opens a wide scope for future electronic and optoelectronic devices. Investigation of their fundamental properties via computer simulations is therefore important. In this study, quantum chemical calculations are performed using density functional theory (DFT) to investigate the electronic and optical properties of oligomers of Ber+ and 3,4-ethylenedioxythiophene (EDOT) and to explore the possibilities for homo-polymerization of Ber+ and its copolymerization with EDOT. It has been revealed that homo-polymerization is not favoured but copolymerization with EDOT is possible. As such, Ber+ was copolymerized with EDOT and the copolymers formed by electro-polymerization are extensively characterised and the D-A behaviour of the copolymers verified. Furthermore, the theoretical predictions have been compared with the experimental data.

Highly Enantioselective Synthesis of Pharmaceuticals at Chiral-Encoded Metal Surfaces

Enantioselective catalysis is of crucial importance in modern chemistry and pharmaceutical science. Although various concepts have been used for the development of enantioselective catalysts to obtain highly pure chiral compounds, most of them are based on homogeneous catalytic systems. Recently, we successfully developed nanostructured metal layers imprinted with chiral information, which were applied as electrocatalysts for the enantioselective synthesis of chiral model compounds. However, so far such materials have not been employed as heterogeneous catalysts for the enantioselective synthesis of real pharmaceutical products. In this contribution, we report the asymmetric synthesis of chiral pharmaceuticals (CPs) with chiral imprinted Pt-Ir surfaces as a simple hydrogenation catalyst. By fine-tuning the experimental parameters, a very high enantioselectivity (up to 95 % enantiomeric excess) with good catalyst stability can be achieved. The designed materials were also successfully used as catalytically active stationary phases for the continuous asymmetric flow synthesis of pharmaceutical compounds. This illustrates the possibility of producing real chiral pharmaceuticals at such nanostructured metal surfaces for the first time.

An Engineered Probiotic Produces a Type III Interferon IFNL1 and Reduces Inflammations in in vitro Inflammatory Bowel Disease Models

The etiology of inflammatory bowel diseases (IBDs) frequently results in the uncontrolled inflammation of intestinal epithelial linings and the local environment. Here, we hypothesized that interferon-driven immunomodulation could promote anti-inflammatory effects. To test this hypothesis, we engineered probiotic Escherichia coli Nissle 1917 (EcN) to produce and secrete a type III interferon, interferon lambda 1 (IFNL1), in response to nitric oxide (NO), a well-known colorectal inflammation marker. We then validated the anti-inflammatory effects of the engineered EcN strains in two in vitro models: a Caco-2/Jurkat T cell coculture model and a scaffold-based 3D coculture IBD model that comprises intestinal epithelial cells, myofibroblasts, and T cells. The IFNL1-expressing EcN strains upregulated Foxp3 expression in T cells and thereafter reduced the production of pro-inflammatory cytokines such as IL-13 and -33, significantly ameliorating inflammation. The engineered strains also rescued the integrity of the inflamed epithelial cell monolayer, protecting epithelial barrier integrity even under inflammation. In the 3D coculture model, IFNL1-expressing EcN treatment enhanced the population of regulatory T cells and increased anti-inflammatory cytokine IL-10. Taken together, our study showed the anti-inflammatory effects of IFNL1-expressing probiotics in two in vitro IBD models, demonstrating their potential as live biotherapeutics for IBD immunotherapy.

Visual guidance of honeybees approaching a vertical landing surface

Landing is a critical phase for flying animals, whereby many rely on visual cues to perform controlled touchdown. Foraging honeybees rely on regular landings on flowers to collect food crucial for colony survival and reproduction. Here, we explored how honeybees utilize optical expansion cues to regulate approach flight speed when landing on vertical surfaces. Three sensory-motor control models have been proposed for landings of natural flyers. Landing honeybees maintain a constant optical expansion rate set-point, resulting in a gradual decrease in approach velocity and gentile touchdown. Bumblebees exhibit a similar strategy, but they regularly switch to a new constant optical expansion rate set-point. In contrast, landing birds fly at a constant time to contact to achieve faster landings. Here, we re-examined the landing strategy of honeybees by fitting the three models to individual approach flights of honeybees landing on platforms with varying optical expansion cues. Surprisingly, the landing model identified in bumblebees proved to be the most suitable for these honeybees. This reveals that honeybees adjust their optical expansion rate in a stepwise manner. Bees flying at low optical expansion rates tend to increase their set-point stepwise, while those flying at high optical expansion rates tend to decrease it stepwise. This modular landing control system enables honeybees to land rapidly and reliably under a wide range of initial flight conditions and visual landing platform patterns. The remarkable similarity between the landing strategies of honeybees and bumblebees suggests that this may also be prevalent among other flying insects. Furthermore, these findings hold promising potential for bioinspired guidance systems in flying robots.

Majorana's approach to nonadiabatic transitions validates the adiabatic-impulse approximation

The approach by Ettore Majorana for non-adiabatic transitions between two quasi-crossing levels is revisited and significantly extended. We rederive the transition probability, known as the Landau-Zener-Stückelberg-Majorana formula, and introduce Majorana's approach to modern readers. This result, typically referred as the Landau-Zener formula, was published by Majorana before Landau, Zener and Stückelberg. Moreover, we go well beyond previous results and we now obtain the full wave function, including its phase, which is important nowadays for quantum control and quantum information. The asymptotic wave function correctly describes the dynamics away from the avoided-level crossing, while it has limited accuracy in that region.

Effect of morphological variation in three-dimensional multiwall carbon nanotubes as the host cathode material for high-performance rechargeable lithium–sulfur batteries†

Lithium–sulfur batteries (LSBs) demonstrate potential as next-generation energy storage systems due to the high theoretical capacity and energy density of the sulfur cathode (1672 mAh g⁻¹ and 2600 W h kg⁻¹, respectively) in addition to the low-cost, natural abundance, and environmentally benign characteristics of sulfur. However, the insulating nature of sulfur requires an efficient conductive and porous host material such as three-dimensional carbon nanotubes (3D CNTs). Identifying parameters that provide high conduction pathways and short diffusion lengths for Li-ions within the CNT structure is essential for a highly efficient CNT-S cathode in a LSB. Herein, the effect of morphological variation in 3D CNTs as a sulfur host material is studied, and parameters that affect the performance of a CNT-S cathode in LSB are investigated. Four different 3D CNTs are synthesized via the chemical vapor deposition (CVD) technique that vary in specific surface area (SSA), CNT diameter, pore sizes, and porosity. The superior 3D CNT-S (CNT-S-50) cathode, which possessed high surface area and porosity as compared to the rest of the 3D CNT-S cathodes, with ∼38 wt% (6.27 mg cm⁻²) sulfur loading, demonstrated an areal and specific discharge capacity of 8.70 mAh cm⁻² and 1387 mAh g⁻¹ at 0.1C, respectively. Results from this work demonstrate that the combination of high surface area and porosity are two crucial parameters in 3D CNTs as an efficient sulfur host material for LSB cathodes.

Among various parameters of 3D CNTs as a conductive sulfur host material in LSB cathodes, high surface area, high porosity, and small pore size distribution, among others, are the most critical parameters, enhancing LSB performance.

Anisotropic Hyperfine Interaction of Surface-Adsorbed Single Atoms

Hyperfine interactions have been widely used in material science, organic chemistry, and structural biology as a sensitive probe to local chemical environments. However, traditional ensemble measurements of hyperfine interactions average over a macroscopic number of spins with different geometrical locations and nuclear isotopes. Here, we use a scanning tunneling microscope (STM) combined with electron spin resonance (ESR) to measure hyperfine spectra of hydrogenated-Ti on MgO/Ag(100) at low-symmetry binding sites and thereby determine the isotropic and anisotropic hyperfine interactions at the single-atom level. Combining vector-field ESR spectroscopy with STM-based atom manipulation, we characterize the full hyperfine tensors of ⁴⁷Ti and ⁴⁹Ti and identify significant spatial anisotropy of the hyperfine interactions for both isotopes. Density functional theory calculations reveal that the large hyperfine anisotropy arises from highly anisotropic distributions of the ground-state electron spin density. Our work highlights the power of ESR-STM-enabled single-atom hyperfine spectroscopy in revealing electronic ground states and atomic-scale chemical environments.

Quantum Algorithm for Numerical Energy Gradient Calculations at the Full Configuration Interaction Level of Theory

A Bayesian phase difference estimation (BPDE) algorithm allows us to compute the energy gap of two electronic states of a given Hamiltonian directly by utilizing the quantum superposition of their wave functions. Here we report an extension of the BPDE algorithm to the direct calculation of the energy difference of two molecular geometries. We apply the BPDE algorithm for the calculation of numerical energy gradients based on the two-point finite-difference method, enabling us to execute geometry optimization of one-dimensional molecules at the full-CI level on a quantum computer. Results of numerical quantum circuit simulations of the geometry optimization of the H₂ molecule with the STO-3G and 6-31G basis sets, the LiH and BeH₂ molecules at the full-CI/STO-3G level, and the N₂ molecule at the CASCI(6e,6o)/6-311G* level are given.

Stable optical lateral forces from inhomogeneities of the spin angular momentum

Transverse spin momentum related to the spin angular momentum (SAM) of light has been theoretically studied recently and predicted to generate an intriguing optical lateral force (OLF). Despite extensive studies, there is no direct experimental evidence of a stable OLF resulting from the dominant SAM rather than the ubiquitous spin-orbit interaction in a single light beam. Here, we theoretically unveil the nontrivial physics of SAM-correlated OLF, showing that the SAM is a dominant factor for the OLF on a nonabsorbing particle, while an additional force from the canonical (orbital) momentum is exhibited on an absorbing particle due to the spin-orbit interaction. Experimental results demonstrate the bidirectional movement of 5-μm-diameter particles on both sides of the beam with opposite spin momenta. The amplitude and sign of this force strongly depend on the polarization. Our optofluidic platform advances the exploitation of exotic forces in systems with a dominant SAM, facilitating the exploration of fascinating light-matter interactions.

Deterministic Loading of Microwaves onto an Artificial Atom Using a Time-Reversed Waveform

Loading quantum information deterministically onto a quantum node is an important step toward a quantum network. Here, we demonstrate that coherent-state microwave photons with an optimal temporal waveform can be efficiently loaded onto a single superconducting artificial atom in a semi-infinite one-dimensional (1D) transmission-line waveguide. Using a weak coherent state (the number of photons (N) contained in the pulse ≪1) with an exponentially rising waveform, whose time constant matches the decoherence time of the artificial atom, we demonstrate a loading efficiency of 94.2% ± 0.7% from 1D semifree space to the artificial atom. The high loading efficiency is due to time-reversal symmetry: the overlap between the incoming wave and the time-reversed emitted wave is up to 97.1% ± 0.4%. Our results open up promising applications in realizing quantum networks based on waveguide quantum electrodynamics.

Magnetic-field-dependent stimulated emission from nitrogen-vacancy centers in diamond

Negatively charged nitrogen-vacancy (NV) centers in diamond are promising magnetic field quantum sensors. Laser threshold magnetometry theory predicts improved NV center ensemble sensitivity via increased signal strength and magnetic field contrast. Here, we experimentally demonstrate laser threshold magnetometry. We use a macroscopic high-finesse laser cavity containing a highly NV-doped and low absorbing diamond gain medium that is pumped at 532 nm and resonantly seeded at 710 nm. This enables a 64% signal power amplification by stimulated emission. We test the magnetic field dependency of the amplification and thus demonstrate magnetic field-dependent stimulated emission from an NV center ensemble. This emission shows an ultrahigh contrast of 33% and a maximum output power in the milliwatt regime. The coherent readout of NV centers pave the way for novel cavity and laser applications of quantum defects and diamond NV magnetic field sensors with substantially improved sensitivity for the health, research, and mining sectors.

An Extension of Combinatorial Contextuality for Cognitive Protocols

This article extends the combinatorial approach to support the determination of contextuality amidst causal influences. Contextuality is an active field of study in Quantum Cognition, in systems relating to mental phenomena, such as concepts in human memory. In the cognitive field of study, a contemporary challenge facing the determination of whether a phenomenon is contextual has been the identification and management of disturbances. Whether or not said disturbances are identified through the modeling approach, constitute causal influences, or are disregardableas as noise is important, as contextuality cannot be adequately determined in the presence of causal influences. To address this challenge, we first provide a formalization of necessary elements of the combinatorial approach within the language of canonical causal models. Through this formalization, we extend the combinatorial approach to support a measurement and treatment of disturbance, and offer techniques to separately distinguish noise and causal influences. Thereafter, we develop a protocol through which these elements may be represented within a cognitive experiment. As human cognition seems rife with causal influences, cognitive modelers may apply the extended combinatorial approach to practically determine the contextuality of cognitive phenomena.

Isothiazolone-Nitroxide Hybrids with Activity against Antibiotic-Resistant Staphylococcus aureus Biofilms

Isothiazolones are widely used as biocides in industrial processing systems and personal care products, but their use to treat infections in humans has been hampered by their inherent cytotoxicity. Herein, we report a strategy to alleviate isothiazolone toxicity and improve antibacterial and antibiofilm potency by functionalization with a nitroxide moiety. Isothiazolone-nitroxide hybrids 6 and 22 were prepared over three steps in moderate yields (58 and 36%, respectively) from (Z)-3-(benzylsulfanyl)-propenoic acid. Hybrid 22 displayed better activity (minimum inhibitory concentration (MIC) = 35 μM) than the widely used methylisothiazolinone (MIT 1, MIC = 280 μM) against methicillin-susceptible Staphylococcus aureus (MSSA). Hybrid 22 was even more active against drug-resistant strains, such as vancomycin-resistant Staphylococcus aureus (VRSA, MIC = 8.75 μM) over MIT 1 (MIC = 280 μM). The enhanced antibacterial activity of hybrid 22 over MIT 1 was retained against established MSSA and VRSA biofilms, with minimum biofilm eradication concentration (MBEC) values of 35 and 70 μM, respectively, for 22 (the MBEC value for MIT 1 against both strains was ≥280 μM). No toxicity was observed in human epithelial T24 cells treated with hybrid 22 in concentrations up to 560 μM using a lactate dehydrogenase assay.

Field theory spin and momentum in water waves

Spin is a fundamental yet nontrivial intrinsic angular momentum property of quantum particles or fields, which appears within relativistic field theory. The spin density in wave fields is described by the theoretical Belinfante-Rosenfeld construction based on the difference between the canonical and kinetic momentum densities. These quantities are usually considered as abstract and non-observable per se. Here, we demonstrate, both theoretically and experimentally, that the Belinfante-Rosenfeld construction naturally arises in gravity (water surface) waves. There, the canonical momentum is associated with the generalized Stokes drift phenomenon, while the spin is generated by subwavelength circular motion of water particles. Thus, we directly observe these fundamental field theory properties as microscopic mechanical properties of a classical wave system. Our findings shed light onto the nature of spin and momentum in wave fields, demonstrate the universality of relativistic field theory concepts, and offer a new platform for their studies.

Immobilization of molecular catalysts for artificial photosynthesis

Artificial photosynthesis offers a way of producing fuels or high-value chemicals using a limitless energy source of sunlight and abundant resources such as water, CO2, and/or O2. Inspired by the strategies in natural photosynthesis, researchers have developed a number of homogeneous molecular systems for photocatalytic, photoelectrocatalytic, and electrocatalytic artificial photosynthesis. However, their photochemical instability in homogeneous solution are hurdles for scaled application in real life. Immobilization of molecular catalysts in solid supports support provides a fine blueprint to tackle this issue. This review highlights the recent developments in (i) techniques for immobilizing molecular catalysts in solid supports and (ii) catalytic water splitting, CO2 reduction, and O2 reduction with the support-immobilized molecular catalysts. Remaining challenges for molecular catalyst-based devices for artificial photosynthesis are discussed in the end of this review.

On the Irrationality of Being in Two Minds

This article presents a general framework that allows irrational decision making to be theoretically investigated and simulated. Rationality in human decision making under uncertainty is normatively prescribed by the axioms of probability theory in order to maximize utility. However, substantial literature from psychology and cognitive science shows that human decisions regularly deviate from these axioms. Bistable probabilities are proposed as a principled and straight forward means for modeling (ir)rational decision making, which occurs when a decision maker is in "two minds". We show that bistable probabilities can be formalized by positive-operator-valued projections in quantum mechanics. We found that (1) irrational decision making necessarily involves a wider spectrum of causal relationships than rational decision making, (2) the accessible information turns out to be greater in irrational decision making when compared to rational decision making, and (3) irrational decision making is quantum-like because it violates the Bell-Wigner polytope.

Nitroxide Functionalized Antibiotics Are Promising Eradication Agents against Staphylococcus aureus Biofilms

Treatment of biofilm-related Staphylococcus aureus infections represents an important medical challenge worldwide, as biofilms, even those involving drug-susceptible S. aureus strains, are highly refractory to conventional antibiotic therapy. Nitroxides were recently shown to induce the dispersal of Gram-negative biofilms in vitro, but their action against Gram-positive bacterial biofilms remains unknown. Here, we demonstrate that the biofilm dispersal activity of nitroxides extends to S. aureus, a clinically important Gram-positive pathogen. Coadministration of the nitroxide CTEMPO (4-carboxy-2,2,6,6-tetramethylpiperidin-1-yloxyl) with ciprofloxacin significantly improved the biofilm eradication activity of the antibiotic against S. aureus Moreover, covalently linking the nitroxide to the antibiotic moiety further reduced the ciprofloxacin minimal biofilm eradication concentration. Microscopy analysis revealed that fluorescent nitroxide-antibiotic hybrids could penetrate S. aureus biofilms and enter cells localized at the surface and base of the biofilm structure. No toxicity to human cells was observed for the nitroxide CTEMPO or the nitroxide-antibiotic hybrids. Taken together, our results show that nitroxides can mediate the dispersal of Gram-positive biofilms and that dual-acting biofilm eradication antibiotics may provide broad-spectrum therapies for the treatment of biofilm-related infections.

Anti-Stokes excitation of solid-state quantum emitters for nanoscale thermometry

Color centers in solids are the fundamental constituents of a plethora of applications such as lasers, light-emitting diodes, and sensors, as well as the foundation of advanced quantum information and communication technologies. Their photoluminescence properties are usually studied under Stokes excitation, in which the emitted photons are at a lower energy than the excitation ones. In this work, we explore the opposite anti-Stokes process, where excitation is performed with lower-energy photons. We report that the process is sufficiently efficient to excite even a single quantum system-namely, the germanium-vacancy center in diamond. Consequently, we leverage the temperature-dependent, phonon-assisted mechanism to realize an all-optical nanoscale thermometry scheme that outperforms any homologous optical method used to date. Our results frame a promising approach for exploring fundamental light-matter interactions in isolated quantum systems and harness it toward the realization of practical nanoscale thermometry and sensing.

Evaluating probabilistic programming languages for simulating quantum correlations

This article explores how probabilistic programming can be used to simulate quantum correlations in an EPR experimental setting. Probabilistic programs are based on standard probability which cannot produce quantum correlations. In order to address this limitation, a hypergraph formalism was programmed which both expresses the measurement contexts of the EPR experimental design as well as associated constraints. Four contemporary open source probabilistic programming frameworks were used to simulate an EPR experiment in order to shed light on their relative effectiveness from both qualitative and quantitative dimensions. We found that all four probabilistic languages successfully simulated quantum correlations. Detailed analysis revealed that no language was clearly superior across all dimensions, however, the comparison does highlight aspects that can be considered when using probabilistic programs to simulate experiments in quantum physics.