Browse Articles

Spin-controlled stimulated echo formed in molecular triads through photodriven quantum teleportation

A new protocol for recording correlations in the spin system preserved during photodriven quantum teleportation in molecular triads is proposed. It is assumed that an electron can be transferred from donor (D) to acceptor (A) by photoexcitation and that reduction of the stable radical (R) by the acceptor radical anion can take place. The protocol is based on the three-pulse stimulated spin echo sequence, with the first and third microwave pulses selectively applied to the spin R and the second microwave pulse applied to the spin D. Only those molecules in which the state of spin R is teleported to spin D contribute to the spin echo. The echo is formed only when the spin state of radical R after the first microwave pulse is dephased, transferred to the state of D by the laser flash and conserved by the second microwave pulse, and reversed to the state of radical R by charge recombination and refocused after the third pulse. The proposed procedure allows the state in which the radical is reduced to be studied even when its lifetime is short compared to the spin evolution. It also might be useful for investigating the validity of the Haberkorn approach to determining the spin decoherence rate induced by the recombination of the radical pairs. Possible perspectives on the preservation of the correlation between the electron and the nuclear spins in the context of quantum phenomena in spin chemistry research are discussed.

Testing an adapted obesity prevention intervention in under resourced schools: a pilot clustered randomized controlled trial

Quantifying fast structural relaxations in oxide V2O3 thin films

Vanadium sesquioxide (V2O3) attracts considerable interest due to its high technological potential in many devices for resistive switching, energy storage, catalysis, etc. To harness the full potential of these materials in functional devices, it is crucial to understand the dynamics of the structural relaxation process exhibited when grown in thin film form. Here, we present a comprehensive study on the fast-structural relaxation phenomenon observed in V2O3 thin films grown by the pulsed laser deposition technique using a Nd:YAG pulsed infrared laser source. To assess the quality of the interface, structural change, and chemical composition, a quantitative analysis of the transmission electron microscopy images was conducted. Strain analysis reveals that structural relaxation in V2O3 thin films occurs rapidly within the initial ∼4 nm from the film–substrate interface. This relaxation mechanism involves the formation of dislocations near the interface. These findings suggest that enhanced strain coupling at the film–substrate interface contributes to the observed relaxation behavior, underscoring the sensitivity of V2O3’s strongly correlated metallic phase to crystalline defects and structural disorder. Understanding these interfacial relaxation dynamics is critical for the design and optimization of V2O3-based functional devices.

Assessment of smoking exposure by urine cotinine levels in severe COVID-19 patients: a case-control study

Mechanistic insights into formose side reactions: Cannizzaro disproportionation and competing pathways

As a leading candidate for prebiotic synthesis of carbohydrates, the formose reaction has been the subject of extensive investigation. However, formaldehyde’s reactivity enables competing pathways that divert the formose condensation, generating dead-end products. Here, we employ our recently developed roto-translationally invariant potential-driven molecular dynamics to investigate the side pathways in the formose reaction network, identifying several new reaction mechanisms. Complementary density functional theory calculations with transition state optimization demonstrate the Cannizzaro disproportionation (yielding methanol and formate) as the dominant competing pathway, exhibiting a lower Gibbs free energy barrier (16.5 kcal mol−1) than both formaldehyde dimerization (26.9 kcal mol−1) and the formose autocatalytic cycle (18.0 kcal mol−1). In addition, carbon monoxide, carbon dioxide, and hydrogen gas may also form as by-products, with respective formation barriers of 24.2, 28.4, and 32.3 kcal mol−1. These results advance our understanding of reaction competition in prebiotic carbohydrate synthesis.

Optimizing MXene graphene based fluids for solar energy conversion and storage using a novel intelligent framework

Glassy dynamics and a growing structural length scale in supercooled nanoparticles

We use molecular dynamics simulation to study the relationship between structure and dynamics in supercooled binary Lennard-Jones nanoparticles over a range of particle sizes. The glass transition temperature of the nanoparticles is found to be significantly lowered relative to the bulk, decreasing as N−1/3 with decreasing particle size. This allows the nanoparticles to sample low energy states on the potential energy landscape, and we are able to study their relaxation times, measured in terms of the intermediate scattering function, and their structure, measured in terms of locally favored structures, to low temperatures. Our work shows that the growing relaxation times in the supercooled nanoparticles are coupled with the growth of physical clusters formed from favored local structures in a way that is well-described by the random first-order transition entropic droplet model, but with exponents that are dependent on the nanoparticle size.

Optimization of SiO2 based water–diesel emulsified fuel for engine performance and emission characteristics using soft computing approaches

Retraction Note: Parkin and PINK1 mitigate STING-induced inflammation

Observation of thickness dependent anomalous spin filtration in MoS2 ultra-thin films

This study exposes novel spin filtering phenomena in ultra-thin MoS2 films deposited on indium tin oxide (ITO) substrates. The novelty lies in the explicit dependence of spin polarization and filtering efficiency on the film thickness. MoS2, a transition metal dichalcogenide, exhibits promising spintronic properties due to its intrinsic spin–orbit coupling and the potential to control spin orientation. We prepared MoS2 films of various thicknesses on ITO substrates and investigated their spin-filtering behavior using scanning tunneling spectroscopy (STS). Results reveal that the degree of spin polarization is highly sensitive to the MoS2 layer thickness, with ultra-thin films (4 nm) exhibiting reverse spin polarization compared to thicker films (10–15 nm). This spin flipping is attributed to the structural deformations in MoS2 thin films, such as twisting and folding, that break spatial symmetry and induce chirality. These chiral distortions modulate the electronic states and promote spin-selective transport in the crystal. The findings underscore the tunability of spin filtering in MoS2/ITO structures through geometric control, offering valuable insights for developing chirality-assisted spintronic devices.

2D magnetotelluric forward modeling based on multitask deep learning

Realization of a doped quantum antiferromagnet in a Rydberg tweezer array

Erratum: “First-principles evaluation of the second harmonic generation response of reference organic and inorganic crystals” [J. Chem. Phys. 158, 064707 (2023)]

Insights into efficient removal of cationic and anionic dyes by olive pomace adsorbent

Enhanced nonreciprocal energy radiator by magneto-optical material InAs-based square hollow Si pillars

In recent years, the value of research in the field of nonreciprocal energy radiation has been increasing. However, at present, the study of nonreciprocal structures with polarization independence and small-angle incidence is still to be further researched, which is what this paper focuses on. In this paper, a device consisting of a two-dimensional grating, a magneto-optical material layer, and a metal plate is proposed, which can realize polarization-independent nonreciprocity. Two pairs of complementary nonreciprocal peaks can be obtained for TE and TM polarizations in the wavelength range of 10.3–10.8 μm, with nonreciprocal efficiencies exceeding 89% and up to 92%. Moreover, at the wavelengths of 10.696 and 10.760 μm, the polarization-independent nonreciprocal phenomenon can be formed; meanwhile, the efficiency exceeds 87.5% and reaches up to 92%. At polarization-independent nonreciprocal peaks where resonance occurs, through careful analysis of the distribution of electromagnetic fields and the use of coupled mode theory, we have discovered the physical mechanisms that form nonreciprocal phenomena and verified the data. The results in this paper provide more practical ideas for the research and development of nonreciprocal energy radiation devices.

Work extraction from coupled qubits in equilibrium and nonequilibrium thermal reservoirs

Self-referenced readout of nanopore translocation signals using localized electrometry

For the past two decades, the ionic current blockade-based readout approach has been the basis of nanopore single-molecule sensing technology. Here, we introduce “nanopore electrometry,” a readout method based on measuring the modulation of the local electric field due to the translocation of the target molecule. Through comprehensive multiphysics and molecular dynamics simulations, we establish the unique strengths of nanopore electrometry that can open up new frontiers in nanopore based molecular detection. For instance, electric field concentration inside the nanopore combined with the rapid decay of the field due to charge screening leads to an asymmetric sensitivity of nanopore electrometry to the charge of the target, i.e., one can sense only cations or only anions depending on the location of the electric field sensor or the direction of the external electric field. Furthermore, simultaneous measurements from multiple local electric field sensors can be utilized for self-referenced error correction and to compensate for translocation velocity fluctuations. Finally, nanopore electrometry can also be used to detect translocations without requiring liquid electrolytes.

The identification of metabolites from gut microbiota in autism spectrum disorder via network pharmacology

Nutrients activate distinct patterns of small-intestinal enteric neurons

From binding to detox: A predictive framework for supramolecular drug capture by cucurbiturils

The pumpkin-like supramolecular container Cucurbit[8]uril (CB8) is a promising drug carrier and detoxifier that stably coordinates a series of structurally diverse guests with high association constants. Its methylated form, Me4CB8, achieves better solubility yet maintains its biocompatibility, thus serving as a promising supramolecular container. Host–guest binding involving the methylated ring is difficult to model due to the lack of an accurate transferable force field and the complex binding-mode space when coordinating structurally complex abused drugs (e.g., fentanyl with multiple aromatic rings). In this work, we present a thorough characterization of cucurbituril host–guest coordinations in a batch of practical detoxification situations with enhanced sampling techniques in conjunction with the most accurate fixed-charge parameter set. An enhanced sampling technique is coupled with high-accuracy recalibrated force fields (B97-3c calculations for host and r2SCAN-3c for abused drugs, achieving a practical accuracy limit of fixed-charge modeling of host–guest systems). While the predicted binding thermodynamics agree with experimental values, additional all-atom insights into the multi-modal binding behavior and the nature of host–guest interactions that are absent in experimental measurements are characterized using a combination of force-field energetics and quantum mechanics-based energy decomposition analysis. Overall, this workflow provides a broadly applicable strategy for the mechanistic understanding of supramolecular detoxification systems and, more importantly, predictive modeling that enables the rational design of therapeutic carriers and antidotes.