A density functional theory study of amino acids on Mg and Mg-based alloys

Authors: John Bolin, Amanda Goold, Olof Hildeberg, Alva Limbäck, Elsebeth Schröder

Published: January 12, 2026

Magnesium (Mg) has mechanical properties similar to bone tissue, and Mg ions take part in the metabolism. This makes Mg of interest for biocompatible degradable body implants, provided that its high corrosion rate can be inhibited. Slightly alloying Mg and adding surface coatings can slow down the corrosion processes without significantly changing the mechanical properties. Use of coating molecules that are native to the body increase the likelihood of making the surface biocompatible, for example by use of amino acids. We here present a density functional theory (DFT) study of the adsorption on Mg(0001) of the amino acids glycine, L-proline, and L-hydroxyproline (Hyp), the main amino acid content of collagen. We investigate how binding of the functional groups of Hyp are affected when Mg(0001) is slightly alloyed with zinc, lithium or aluminium, and we also model the immersion of the systems in a water environment to see how this affects the binding.

Quantum science with arrays of metastable helium-3 atoms

Authors: Zheyuan Li, Rupsa De, Rishi Sivakumar, William Huie, Hao-Tian Wei, Justin D. Piel, Chris H. Greene, Kaden R. A. Hazzard, Zoe Z. Yan, Jacob P. Covey

Published: January 11, 2026

The motion of atoms in programmable optical tweezer arrays offers many new opportunities for neutral atom quantum science. These include inter- and intra-site atom motion for resource-efficient implementations of fermionic and bosonic modes, respectively, as well as tweezer transport for efficient compilation of arbitrary circuits. However, the exploitation of atomic motion for all three purposes and others is limited by the inertia of the atoms. We present a comprehensive architectural blueprint for the use of fermionic metastable helium-3 ($^3$He$^*$) atoms -- the lightest trappable atomic species -- in programmable optical tweezer arrays. This includes a concrete analysis of atomic structure considerations as well as Rydberg-mediated interactions. We show that inter-tweezer hopping of $^3$He$^*$ atoms can be $\gtrsim3\times$ faster than previous demonstrations with lithium-6. We also demonstrate a new toolbox for encoding and manipulating qubits directly in the tweezer trap potential, uniquely enabled by the light mass of $^3$He$^*$. Finally, we provide several examples of new opportunities for fermionic quantum simulation and computation that leverage the transport and inter-tweezer hopping of $^3$He$^*$ atom arrays. These tools present new methods to improve the resource efficiency of neutral atom quantum science that may also enable quantum simulations of lattice gauge theories and quantum chemistry outside the Born-Oppenheimer approximation

Goldene monolayer as a highly effective catalyst for polysulfide anchoring and conversion: A theoretical study

Authors: Nicolas F. Martins, José A. dos S. Laranjeira, Bill D. A. Huacarpuma, Kleuton A. L. Lima, Luiz A. Ribeiro, Julio R. Sambrano

Published: January 8, 2026

We use first-principles density functional theory to investigate how lithium sulfide and polysulfide clusters (Li2S, Li2S2, Li2S4, Li2S6, Li2S8, and S8) bind to Goldene, a new two-dimensional gold allotrope. All Li-S species exhibit robust binding to Goldene. The adsorption energies range from -4.29 to -1.90 eV. S8 that is alone interacts much less strongly. Charge density difference and Bader analyses indicate that substantial charge is transferred to the substrate, with a maximum 0.92 e for Li-rich clusters. This transfer induces polarization at the interface and shifts the work function to 5.30-5.52 eV. Projected density-of-states calculations indicate that Au-d and S-p states strongly mix near the Fermi level. This hybridization indicates that the electronic coupling is strong. Based on these results, the reaction free-energy profile for the stepwise conversion of S8 to Li2S on Goldene is thermodynamically favorable. The overall stabilization is -3.64 eV, and the rate-determining barrier for the Li2S2 -> Li2S step is 0.47 eV. This shows that Goldene is an effective surface for anchoring and mediating lithium polysulfide reactions.

First Thin-Film Lithium Tantalate Polarization Controller Enabling Reset-Free Mrad/s Tracking for Optical Interconnects

Authors: Zichao Gao, Siyu Lu, Mingming Zhang, Gengqi Yao, Chicheng Zhang, Miao Deng, Siyu Chen, Yiqi Dai, Shiqi Yue, Chijun Li, Yuqi Li, Ziwen Zhou, Zheli Liu, Xinyang Yu, Xitao Ji, Cheng Zeng, Siqi Yan, Jinsong Xia, Ming Tang

Published: January 7, 2026

The rapid escalation of computing power driven by large-scale artificial intelligence is placing unprecedented demands on the bandwidth, latency, and energy efficiency of data-center interconnects (DCIs). Self-homodyne coherent (SHC) transmission is a promising architecture because it preserves the spectral efficiency of coherent detection while greatly simplifying digital signal processing, but its practical deployment is critically limited by random and often ultrafast state-of-polarization (SOP) fluctuations that induce carrier fading and destabilize coherent reception. Here we report the first integrated polarization controller based on thin-film lithium tantalate (TFLT), enabling reset-free polarization tracking at Mrad/s speeds. The four-stage electro-optic device exhibits polarization-dependent loss (PDL) below 0.3 dB, a half-wave voltage below 2.5 V, high modulation bandwidth, and negligible DC drift. To accommodate the finite tuning range of integrated phase shifters, we develop a finite-boundary gradient-descent (FBGD) control algorithm that ensures reset-free SOP evolution with no phase jump. The implemented adaptive polarization controller (APC) is validated through both standalone polarization-tracking measurements and a dual-polarization 16-QAM SHC 400-Gbps transmission system. Transient polarization disturbances can be tracked at speeds up to 2 Mrad/s, while stable reset-free operation under continuous polarization disturbances is maintained up to 1 Mrad/s. This reset-free performance represents more than doubling the state of the art, while the pre-FEC bit-error rates remain below the HD-FEC threshold under realistic DCI conditions and lightning-scale polarization disturbances. These results establish TFLT as a new platform for ultrafast, low-power, reset-free, and drift-free polarization control in coherent optical interconnects and beyond.

Novel fast Li-ion conductors for solid-state electrolytes from first-principles

Authors: Tushar Singh Thakur, Loris Ercole, Nicola Marzari

Published: January 6, 2026

We present a high-throughput computational screening for fast lithium-ion conductors to identify promising materials for application in all solid-state electrolytes. Starting from more than 30,000 Li-containing experimental structures sourced from Crystallography Open Database, Inorganic Crystal Structure Database and Materials Platform for Data Science, we perform highly automated calculations to identify electronic insulators. On these ~1000 structures, we use molecular dynamics simulations to estimate Li-ion diffusivities using the pinball model, which describes the potential energy landscape of diffusing lithium with accuracy similar to density functional theory while being 200-500 times faster. Then we study the ~60 most promising and previously unknown fast conductors with full first-principles molecular dynamics simulations at several temperatures to estimate their activation barriers. The results are discussed in detail for the 9 fastest conductors, including $Li_7NbO_6$ which shows a remarkable ionic conductivity of ~5 mS/cm at room temperature. We further present the entire screening protocol, including the workflows where the accuracy of the pinball model is improved self-consistently, necessary to automatically running the required calculations and analysing their results.

Interplay of Structure and Dynamics in Solid Polymer Electrolytes: a Molecular Dynamics Study of LiPF6/polypropylene carbonate

Authors: Amaury Coste, Thomas Meyer, Claire Villevielle, Fannie Alloin, Stefano Mossa, Benoit Coasne

Published: January 6, 2026

Solid-state batteries (SSB) are emerging as next-generation electrochemical energy storage devices. Achieving high energy density in SSB relies on solid polymer electrolytes (SPE) that are electrochemically stable against both lithium metal and high-potential positive electrodes, two conditions that are difficult to satisfy without chemical degradation. In this work, molecular dynamics simulations are employed to investigate the relationship between structure and dynamics in carbonate-based SPE composed of polypropylene carbonate and lithium hexafluorophosphate (LiPF$_6$), at salt concentrations ranging from 0.32 to 1.21 mol$/$kg. Structural properties are analyzed under ambient pressure at the experimentally relevant temperature $T = 353$ K. Since the slow dynamical processes governing ion transport in these systems are inaccessible to direct molecular dynamics, transport properties are simulated at elevated temperatures up to 900 K and extrapolated to $T = 353$ K using Arrhenius behavior. The results reveal strong ionic correlations, a limited fraction of free ions, and a predominance of negatively charged clusters, especially at high salt concentration. At high temperature, the self-diffusion coefficient of Li$^+$ exceeds that of PF$_6^-$ due to weaker Li$^+$-carbonate and ion-ion interactions. However, at $T = 353$ K, Li$^+$ mobility becomes lower than that of the anion, consistent with typical experimental observations in SPE. As expected, the ionic conductivity $σ$ increases with temperature, while at $T = 353$ K it exhibits a maximum for salt concentrations between 1.0 and 1.1 mol$/$kg. Overall, the estimated physico-chemical parameters highlight the key role of ion correlations in SPE and suggest strategies to optimize electrolyte performance. The Arrhenius extrapolation approach used here provides valuable insight into ion transport mechanisms in solid polymer electrolytes.

Uncooled low-noise thin-film optomechanical resonator for thermal sensing on lithium niobate

Authors: Yue Yu, Ran Yin, Ian Anderson, Yinan Wang, Jack Kramer, Chun-Ho Lee, Xinyi Ren, Zaijun Chen, Michelle Povinelli, Dan Wasserman, Ruochen Lu, Mengjie Yu

Published: January 6, 2026

Optomechanical transduction harnesses the interaction between optical fields and mechanical motion to achieve sensitive measurement of weak mechanical quantities with inherently low noise. Lithium niobate combines low optical loss, strong piezoelectricity, high intrinsic fQ_m factor, and low thermal conductivity, making it promising for exploring optomechanical platforms targeting thermal sensing applications. Here, we developed an integrated optomechanical platform on thin-film lithium niobate with precisely engineered optical, mechanical, and thermal fields within a compact 40 μm by 40 μm footprint. The platform integrates suspended microring resonators with ultrathin central membranes, reducing mechanical stiffness and effective mass while maintaining a high optical factor Q_o of 1e6 and mechanical quality factor Q_m of 1117, which increases to 5.1e4 after oscillation. The design suppresses thermal dissipation into the silicon substrate and enhances thermal sensitivity, achieving a temperature coefficient of frequency of -124 ppm/K and a noise-equivalent power of 6.2 nW/sqrt(Hz) at 10 kHz at room temperature. This compact and scalable platform opens up new opportunities for high-sensitivity thermal sensing, supports heterogeneous integration with infrared absorbers for uncooled infrared detection, and enables fully integrated, all-optical on-chip readout, paving the way toward large-format, low-noise infrared sensing arrays.

Physics-informed neural network surrogate modeling of single particle model for lithium-ion batteries

Authors: Yi Zhuang, Yusheng Zheng, Yunhong Che, Remus Teodorescu

Published: January 4, 2026

Physics-based models play a key role in battery management, yet face challenges in real-time applications due to the high computational cost of solving coupled algebraic-partial differential equations. To accelerate model simulation, this study benchmarks three physics-informed neural network (PINN) architectures for modeling the battery single particle model, including two conventional PINN architectures and a DeepONet-based architecture. Both the accuracy and the generalization of these PINNs have been evaluated and compared under various current conditions. Our results highlight the potential of PINNs in modeling battery physics but also reveal limitations of conventional PINN architectures under highly dynamic current conditions. Among them, the Fourier-enhanced DeepONet achieves superior generalization performance and offers nearly a 10 times speedup compared with numerical solvers. This work provides an example of integrating physics-based models

Fully Coupled Multiphysics Modelling of Fracture Behaviour in Silicon Particles During Lithiation Delithiation Using the Phase Field Method

Authors: Jie Yang, Wei Tan

Published: January 4, 2026

In this study, a multiphysics model fully coupling mass transport, deformation, phase field, and fatigue damage was developed to investigate the cracking and fracturing behaviours of Si particles during the single lithiation-delithiation cycle and fatigue damage during multiple cycles. The effects of particle diameter, charge rate, and pre-existing notches on the failure behaviour of Si particles were systematically analysed. The results showed that the increase in charge rate, particle diameter, and pre-existing notch length leads to larger cracking rates and faster fracturing of the particle. Then, a validated contour map of Si particle's fracture behaviours was developed. Additionally, the influence of pre-existing notch length and charge rate on fatigue damage was examined, and it was found that longer pre-existing notch length and larger charge rate can shorten the particle's cyclic life. Finally, to alleviate the particle fracture, nanopores were introduced in the particle, and the influence of porosity on the fracture behaviours was investigated. The results showed that nanopores can reduce expansion, dissipate global tensile stresses and elongate the crack propagation path. The developed computational framework established a predictive relationship between stress diffusion coupling theory and particle-level degradation, guiding future design and manufacturing of failure-resistant Si-based anodes for lithium-ion batteries.

Inflight performance and future improvements for the INtegral Field Ultraviolet Spectrographic Experiment, the first far ultraviolet integral field spectrograph

Authors: Alex Haughton, Emily M. Witt, Brian T. Fleming, Alex Sico, Michael J. Kaiser, M. S. Oey, Grace Halferty, Dmitry Vorobiev, Kevin France, Takashi Sukegawa, Oswald Siegmund, Adrian Martin

Published: January 2, 2026

Integral field spectroscopy allows for spectral mapping of extended sources in a time efficient manner. An integral field unit (IFU) in the ultraviolet on Habitable Worlds Observatory (HWO) could be used to quickly map extended objects like supernova remnants or galaxies and their surroundings, but there are technical challenges to an ultraviolet IFU. The INtegral Field Ultraviolet Spectrographic Experiment (INFUSE), a sounding rocket project, is the first static configuration far ultraviolet integral field spectrograph. INFUSE features an f/16, 0.49m Cassegrain telescope and a 26-element image slicer feeding 26 replica holographic gratings, with spectra imaged by the largest cross-strip microchannel plate detector flown in space. The first launch of INFUSE occurred from White Sands Missile Range on October 29th, 2023, and demonstrated spectral multiplexing, successfully detecting ionizing gas emission in the XA region of the Cygnus Loop. INFUSE will launch again in fall 2025 to observe NGC 2366, a local analog for Green Pea type galaxies, with several enhancements including a xenon-enhanced lithium fluoride + aluminum coated grating, testing the leading flight coating for HWO for the first time. The INFUSE IFU is designed as a pathfinder for a potential IFU mode on HWO, enabling rapid 3D spectroscopy of extended sources.