Materials Science · Cross-listed from quant-ph
On multipoles, their decomposition by time-reversal symmetry, and the electric toroidal monopole
Vinzenz A. Müller, Nora Taufertshöfer and Nicola A. Spaldin
The multipole decomposition of the single-site density
matrix provides a
symmetry-adapted representation of local electronic degrees of freedom. Conventional, so-called fixed-shell, formulations do not span the full local single-particle operator space, as only operators mapping within the same orbital $l$ are resolved. Here we construct a complete orthogonal basis of real Hermitian multipole operators for the local density
matrix by extending the existing formulation to inter-shell operators. We revisit the multipole decomposition as a decomposition of the operator space by $\mathrm{SO}(3)$ by first decomposing the orbital and
spin operator spaces. Then by coupling them we arrive at the
spin-$\frac{1}{2}$ local single-particle operator space, staying consistent with the existing fixed-shell formulations. We then classify the multipoles by parity and time-reversal
symmetry, which allows for unique identification of multipole moments of the density
matrix that contribute to expectation values of fully
symmetry-resolved observables. As an application, we analyze the two enantiomers of
chiral trigonal tellurium by computing the electric toroidal monopole moment selected by
symmetry.
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Statistical Mechanics · Cross-listed from cs.IT
The Informational Cost of Structure: Representational Complexity in Networked Dynamical Systems
Cyril Rommens, Pietro Traversa, Guilherme Ferraz de Arruda et al. (+1 more)
How much information is required to represent a dynamical system in terms of an interaction structure and an
evolution rule? We address this question using algorithmic information theory. We introduce Representational Complexity, the excess description length of a structure-plus-rule model relative to the shortest possible description of the dynamics itself. This intrinsic description defines a universal lower bound: no exact structural representation can be more concise. If arbitrary rules are allowed, graphs, hypergraphs, and other formalisms can all reach this bound by shifting information between structure and dynamics, so expressiveness alone cannot distinguish them. Meaningful differences arise only when scientific modeling restricts the admissible structures and rules. Within this setting, we identify conditions under which graph and hypergraph descriptions are informationally equivalent, and show how graph-preferred, hypergraph-preferred, and mixed regimes can emerge when those conditions are relaxed. Because Kolmogorov complexity is not computable, we complement the formal results with explicit description-length estimates. Our framework reframes the choice of network representation as a question of informational cost and mechanistic transparency rather than universal expressive power.
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All authors Cyril Rommens, Pietro Traversa, Guilherme Ferraz de Arruda, Yamir Moreno
Materials Science
Beyond the Parasitic Limit: A Nanoprobing Framework for De-embedding Intrinsic Ferroelectric Properties at the Deep Sub-Micrometer Scale
Niklas Kyoushi, Georg Schönweger, Ole Gronenberg et al. (+4 more)
The continued scaling of ferroelectric devices is critical for next-generation computing architectures, yet it is fundamentally challenged by a metrological bottleneck: at the deep sub-micrometer scale, intrinsic material properties are heavily masked by extrinsic parasitic impedances and
geometric fringing fields. Here, we introduce a quantitative, in-situ nanoprobing framework capable of resolving the true electrical response of ferroelectric capacitors down to 165 nm in diameter without the need for lithographic bond pads. Using 20 nm thick AlScN as a model system, we establish a non-linear 'Screened Power Law' model to decouple attofarad-level device capacitances from massive near-field probe interactions. Furthermore, we demonstrate that the apparent degradation of dielectric loss at the nanoscale is a
geometric dilution artifact, which we overcome through a conductance scaling analysis. Finally, we apply this framework to large-signal characterization, utilizing leakage-compensation and noise filtering protocols to extract pristine intrinsic hysteresis (C-V and J-E) loops in the discrete few-grain limit. These findings provide a universal analytical toolkit required to overcome the measurement limits of deep-submicron ferroelectrics.
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All authors Niklas Kyoushi, Georg Schönweger, Ole Gronenberg, Dirk Meyners, Adrian Petraru, Fabian Lofink, Simon Fichtner
Materials Science
Physics adapted generative AI for metal insulator transition materials under label scarcity
Gourab Datta, Sarah Sharif, Zhisheng Shi et al. (+1 more)
Metal-
insulator-transition (MIT) materials are promising candidates for switchable electronics, neuromorphic hardware, and reconfigurable photonics, yet experimentally verified examples remain limited and the underlying mechanisms are often complex. We argue that generative AI for MIT discovery should move beyond the search for stable
crystal structures alone and instead prioritize mechanism-informed phase-transition hypotheses. A modular physics-adapted framework, combined with staged verification of phase competition, electronic contrast, transition-pathway plausibility, and control accessibility, can guide credible discovery under severe label scarcity.
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All authors Gourab Datta, Sarah Sharif, Zhisheng Shi, Yaser Banad
Disordered Systems and Neural Networks · Cross-listed from q-bio.MN
Cellular Adaptation to Signal Fluctuations as Learning
Tuan Minh Pham and David Saad
Cells represent one of the most fundamental units of life. Underlying their robust performance against environmental variability, such as temporal fluctuations of chemical signals, between different
cell types, is a dynamical interrelation between the two components of an intracellular pathway: a gene-regulatory network and its upstream signal transducers. To understand how a single
cell utilizes this feedback to self-regulate its gene-expressions, we develop a multiscale model of the pathway's components, in which the adaptive variables responsible for signal interpretation follow a feedback-induced learning process. We then derive a macroscopic theory capturing the covariations between these components - so-called collective modes. Our theory shows how
cells can achieve robust output against signal fluctuations via self-regulation rather than simple noise suppression. Such robustness corresponds to a transition from random- to structured collective modes beyond a critical adaptation rate.
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Mesoscale and Nanoscale Physics
Nonlocal Orbital-Angular-Momentum Dichroism of Vortex Light in Strained Crystals
Habib Rostami
Vortex light carries orbital angular momentum (OAM) in its transverse phase. We show that the transverse phase cannot generate OAM-odd absorption in any continuously translation-invariant system, even when optical nonlocality and multipole light–matter coupling are included. The combination of broken continuous translation
symmetry and finite-range optical nonlocality permits OAM dichroism through transverse-momentum mixing; in nonuniformly strained Dirac materials, the dichroism factorizes into a nonlocal elasto-optic tensor and the overlap of the strain texture with the
vortex transverse phase current.
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Statistical Mechanics · Cross-listed from quant-ph
Thermalization hierarchy from irreducible degrees of freedom
Pedro Fittipaldi de Castro and Wladimir A. Benalcazar
The decomposition of the
Hilbert space of a
quantum many-body system into the irreducible representations of its bond and commutant
algebras yields a finer structure of dynamically isolated subspaces than the mere decomposition into
symmetry sectors. While it has been recognized that subspaces associated with low bond-irrep dimensions $D_\lambda$ tend to violate the eigenstate thermalization hypothesis (ETH), here we show that $D_{\lambda}$ controls thermalization continuously across the full spectrum of dynamical subspaces. Using SU(2)-symmetric
spin-1/2 chains as a paradigmatic example, we demonstrate that $\mathrm{log} \ D_{\lambda}$ quantitatively accounts for the average eigenstate
entanglement entropy within each sector, establishing a thermalization hierarchy that interpolates from exact
quantum many-body scars at $D_{\lambda}=1$ to volume-law ergodic states at large $D_{\lambda}$. To make this concrete, we introduce the notion of irreducible degrees of freedom (IDOF), defined as the number of independently-varying spatial coordinates parametrizing a many-body state within a given bond-
algebra sector, which provides a microscopic interpretation of $D_{\lambda}$ and of the resulting thermalization hierarchy. Finally, we show that by selectively breaking
symmetries while preserving chosen bond-
algebra sectors, one can embed families of nonthermal eigenstates at prescribed
entanglement levels into an otherwise ergodic spectrum, generalizing restricted spectrum-generating
algebras from towers of individual states to entire dynamical subspaces.
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Strongly Correlated Electrons
Fixed-point tensor network for compactified boson conformal field theory
Gong Cheng, Dong-Yu Bao and Zheng-Cheng Gu
Fixed-point (FP) tensor networks provide a discrete spacetime representation of conformal field theories (CFTs), offering a new route toward understanding
holographic duality, generalized
symmetries, and even
quantum gravity. In this work, we construct FP tensors for the 2D compactified
boson theory at a generic compactification radius, an archetypal irrational CFT, using boundary (open-string) data with conformal boundary conditions. We show that the resulting tensors reproduce the closed-string spectrum with high accuracy and generate stable renormalization-group (RG) flows under the tensor complex renormalization
algorithm. Moreover, we identify a controllable exactly marginal deformation at the level of a single tensor, enabling flows that move continuously along the $c=1$
moduli space. This framework establishes a concrete
lattice-level route toward describing a broad class of 2D irrational CFTs.
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Mesoscale and Nanoscale Physics
Robustness of quantized Hall resistivity under cavity coupling at zero temperature
Juan Román-Roche, Jie Wang, Michael Ruggenthaler et al. (+2 more)
Recent experiments have shown that strong light-matter coupling in electromagnetic cavities can modify transport properties of
quantum Hall systems through the formation of Landau polaritons, prompting questions about the robustness of topological protection. While earlier theory demonstrated that the
Hall conductivity can be modified at finite temperature and finite polariton lifetime (or finite broadening), experiments primarily probe the resistivity tensor. Our phenomenological model reveals an asymmetry between conductivity and resistivity in
quantum Hall systems under strong light-matter interaction, showing that at zero temperature the
Hall resistivity remains completely immune to cavity-induced modifications arising from polariton broadening, independent of the light-matter coupling strength. These results provide a deeper explanation for the absence of renormalization in the von Klitzing constant in experiments probing the even QH plateaus through the
Hall resistivity at low temperature, and clarify the distinct roles of dissipation and strong light-matter coupling in hybrid light-matter systems.
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All authors Juan Román-Roche, Jie Wang, Michael Ruggenthaler, Angel Rubio, Vasil Rokaj
Mesoscale and Nanoscale Physics · Cross-listed from physics.ins-det
A high-sensitivity resistance bridge for nanoscale thermal microscopy
Wilfrid Poirier, Victor Guillemot, Mohammed Mghalfi et al. (+2 more)
Measurements of heat flux between micro-objects, in
vacuum or in air, are challenging because of their small size and the low thermal conductance of the medium between them. One way to address this issue consists in using a scanning thermal microscope (SThM) equipped with a temperature dependent resistance thermometer. However, this requires an instrument able to both injecting a defined heating Joule power and performing highly-sensitive resistance measurements. Here, we present such an instrument based on a Wheatstone bridge equipped with three Kelvin arms. It can perform resistance measurements in the range from 100 $\Omega$ to 1000 $\Omega$ not only in direct current but also in alternating current regimes at frequencies up to a few tenths of kHz. We first show that measurements of resistance standards are accurate to within one part in $10^4$ with a relative experimental standard deviation which can be as low as one part in $10^8$ for one second measurement. The instrument is then tested with a SThM thermometer. With the support of an electro-thermal model considering thermal time constants of the thermometer, we explain the frequency dependence of detected signals and optimize the measurement protocols of temperature and heat flux. By measuring sub-mK temperature variations, this instrument is then used to determine with a few nanowatts uncertainty the near-field radiative heat flux between a heated glass microsphere and a glass substrate, which is caused by the coupling of surface
phonon-polaritons.
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All authors Wilfrid Poirier, Victor Guillemot, Mohammed Mghalfi, Valentina Valentina Krachmalnicoff, Yannick De Wilde
Mesoscale and Nanoscale Physics
Graphene Electric Double-Layer Transistors for Enhanced-Sensitivity Label-Free Detection of Human Serum Albumin
Arslan Liaquat, Ghassem Baridi, Federico Rapuzzi et al. (+14 more)
Accurate detection of human serum albumin (HSA) is essential for the early diagnosis and monitoring of renal and hepatic disorders. We present a
graphene-based electrolyte-gated field-effect transistor (EGFET) for label-free, real-time quantification of HSA under non-Faradaic operation. Devices exploit the high interfacial capacitance of the electric double layer (EDL) to transduce electrostatic perturbations induced by albumin adsorption into measurable conductance modulation. Negatively charged HSA molecules induce systematic modulation of the
graphene channel, producing a concentration-dependent displacement of the Dirac voltage consistent with p-type doping. To establish a molecular-level interpretation of the sensing response, Brownian Dynamics simulations show that HSA adsorbs onto
graphene through multiple adsorption orientations associated with heterogeneous interfacial charge distributions and variable dipole
alignments relative to the surface. Adsorption is energetically stabilized by van der Waals interactions. Analysis of transfer characteristics across concentrations ranging from 0.01 to 30mgmL-1 reveals a correlation between surface charge density and carrier transport modulation within the electric double layer. Optimized devices exhibit a limit of detection of 0.0087 mg mL-1 and a linear dynamic range extending to 10 mg mL-1. The response remains non-Faradaic under sub-volt operation with reversible and reproducible behavior. The use of an inverse-mobility analytical metric highlights the role of disorder-enhanced carrier scattering in signal amplification, enabling sensitive electrostatic detection while preserving reversible device operation. These results establish
liquid-gated
graphene EGFETs as a promising platform for quantitative
protein sensing and provide insight into disorder-mediated transport mechanisms in
graphene bioelectronic devices.
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All authors Arslan Liaquat, Ghassem Baridi, Federico Rapuzzi, Daniele Goldoni, Vito Clerico, El Hadj Abidi, Yahya Moubarak Meziani, Mario Amado, Enrique Diez, Naveen Kumar, Camilia Coletti, Beatrice Cipriani, Hender Lopez, Giorgia Brancolini, Leonardo Martini, Luigi Rovati, Francesco Rossella
Quantum Gases · Cross-listed from quant-ph
Semiclassical Langevin dynamics of long-range dissipative time crystals
Reyhaneh Khasseh, Rosario Fazio and Angelo Russomanno
We develop a semiclassical Langevin approach to study finite-size effects in dissipative time-crystalline
spin systems. For a
spin-$1/2$ model with power-law Lindblad operators, we find finite-size oscillations exponentially decaying in time, and their decay rate decreases algebraically with system size in the long-range regime. The scaling exponent of this decay time provides a direct diagnostic of the robustness of the time-crystalline, and we find that this robustness extends beyond the range of power-law dissipation exponents where the system dynamics is mean-field in the thermodynamic limit. We also apply our approach to a
spin-one model with local dissipation and long-range
Hamiltonian interactions, formulating it in terms of Gell-Mann variables. In this case, finite-size stability is quantified through the deviation time from the mean-field behavior and the behavior of the dominant
Fourier peak. We find that both quantities scale as a power law with the system size – marking thereby a time-
crystal behavior – when the exponent of the power-law interaction is below a certain threshold, that turns out to be in agreement with previous cumulant-expansion findings. Our results show that semiclassical Langevin dynamics provides a useful finite-size probe of dissipative time
crystals in regimes beyond exact Lindblad simulations.
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Materials Science
From Stacking Disorder to Cubic Order: Ice Crystallization from Deeply Supercooled Water
Yulin Lin, Weimin Guo, Suvo Banik et al. (+9 more)
Crystallization far from
equilibrium can generate morphologies that defy classical
crystal habits, yet the microscopic mechanisms linking atomic-scale disorder to emergent macroscopic order remain elusive. Here we use in situ cryogenic transmission electron microscopy with a membrane-encapsulated microdroplet platform to directly visualize the freezing of deeply supercooled water at molecular resolution. We show that homogeneous nucleation produces stacking-disordered ice composed of mixed hexagonal and cubic sequences, in which cubic ice initially exists only as isolated monolayers. The gradual thickening of these cubic layers constitutes the key kinetic mechanism that governs the entire crystallization pathway. As thickening proceeds, nanoscale, defect-free cubic ice germs nucleate on the basal planes of the disordered
lattice. These faceted cubic germs act as facet-registered kinetic seeds that enforce cubic twinning and sequentially multiply growth branches. This kinetic pathway reproducibly generates robust eight-branched dendrites with global cubic (octahedral)
symmetry, even though each branch remains highly stacking-disordered. At later stages, latent heat release drives a crossover to the thermodynamically favored hexagonal phase; remarkably, the pre-established global cubic
symmetry is retained. These results reveal how strong kinetic driving forces convert microscopic disorder into emergent macroscopic
symmetry, providing a general framework for understanding and controlling rapid crystallization far from
equilibrium.
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All authors Yulin Lin, Weimin Guo, Suvo Banik, Tao Zhou, Thomas E. Gage, Lei Yu, Maksim A. Sultanov, Martin Holt, Subramanian Sankaranarayanan, Peng Zhang, Ilke Arslan, Jianguo Wen
Materials Science
Dyna-Mat: End-to-end benchmarking of foundation machine learning interatomic potentials in finite-temperature ensembles
Mikołaj J. Gawkowski, Nongnuch Artrith, Silvia Bonfanti et al. (+14 more)
Foundation machine learning interatomic potentials (MLIPs) are increasingly being used as drop-in replacements for first-principles calculations, enabling simulations of materials at length and time scales that were previously inaccessible. However, due to lack of ground truth data, their accuracy on structural and dynamical observables in finite thermodynamic ensembles is yet to be established. Here, we introduce Dyna-Mat-v1.0, a
benchmark dataset of condensed-phase first-principles molecular dynamics trajectories designed to test foundation MLIPs at realistic finite-temperature conditions. Using this
dataset, we evaluate 15 foundation MLIPs across four model tiers by comparing both single-point energy and force errors on first-principles configurations and observables generated from MLIP-driven trajectories. We find that "on average" models with lower single-point force errors also yield lower errors for structural and dynamical observables. However, there are individual systems for which low force errors lead to qualitative failures in the predicted structure. Pressure remains poorly described across most models, pointing to limitations in the density functional theory stress labels available in current large-scale training
datasets. Finally, we construct an accuracy-cost Pareto frontier to identify the best trade-offs for molecular dynamics with foundation MLIPs, finding that the latest generation of cross-trained models is close to Pareto-optimal according to the accuracy metrics considered here. Overall, Dyna-Mat-v1.0 shows that end-to-end finite-temperature validation is essential for quantifying the predictive behaviour of foundation MLIPs, and provides a simple, scalable route for assessing them beyond static and harmonic
benchmarks relevant to materials design.
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All authors Mikołaj J. Gawkowski, Nongnuch Artrith, Silvia Bonfanti, Abhijeet Sadashiv Gangan, Hendrik H. Heenen, Joseph Kioseoglou, Ivor Lončarić, Hemanadhan Myneni, Janosh Riebesell, Mariana Rossi, Matthias Rupp, Jonathan Schmidt, Shubham Sharma, Benjamin X. Shi, Antoni Wadowski, Lukas Hörmann, Venkat Kapil
Mesoscale and Nanoscale Physics
Evidence of length scale effect in contact electrification in conducting thin film heterostructures
Paul C. Lou, Ravindra G. Bhardwaj, Anand Katailiha et al. (+2 more)
Contact electrification between two conducting materials is expected to exhibit length scale effect because the screening effect will diminish in conductors as a function of material dimensions. As a consequence, the interfacial charge accumulation will diffuse away from interface/surface to a critical penetration depth as a function of material dimension. This work experimentally demonstrates the length scale effect in a permalloy and degenerately doped p-Si
heterostructure system due to the flexoelectricity mediated contact electrification. The contact electrification induced interlayer charge transfer is observed through the whole thickness in case of 400 nm thick p-Si samples. Whereas, the charge carrier diffuses to a depth of 51 nm from the interface in case of 2 um thick Si. The length scale effect also leads to metal-
insulator transition in p-Si layers in both cases. These results present a new opportunity to tailor the physical properties in conducting materials using contact electrification.
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All authors Paul C. Lou, Ravindra G. Bhardwaj, Anand Katailiha, W.P. Beyermann, Sandeep Kumar
Soft Condensed Matter · Cross-listed from physics.flu-dyn
Experimental and numerical study of the dynamics of sedimenting pairs of semi-flexible fibers close to attractive `aligned' relative configuration
Harish N. Mirajkar, Chandra Shekhar, Yevgen Melikhov et al. (+2 more)
Dynamics of two short semi-flexible fibers settling under
gravity in a viscous fluid are investigated at Reynolds numbers Re << 1. We focus on fibers initially relatively close to each other, and we check if later they approach an aligned horizontal configuration, previously identified numerically (Bukowicki and Ekiel-Jezewska, Soft Matter 46 (2019) 9379) as attractive for symmetric initial conditions of moderately elastic filaments. In our experiments, two semi-flexible ball chains sediment in a highly viscous silicone oil. They are initially straight and close to a parallel horizontal relative configuration. Their motion and shape deformation are recorded using two synchronized cameras. For most of the trials, ball chains stay together, with damped oscillations around the symmetric aligned configuration. For a few initial conditions, the ball chains move away horizontally or vertically. To study the behavior over a longer time, we perform numerical simulations, modeling moderately elastic filaments as chains of identical beads, with the centers of consecutive beads connected by springs and with the fibers' elastic resistance to bending. Different initial positions and orientations are considered. Their dynamics are determined by the multipole expansion of the Stokes equations, implemented in the precise Hydromultipole numerical code. For short times, we observe the similar dynamics of semi-flexible ball chains and moderately elastic filaments. We provide examples of long-time numerical simulations illustrating that elastic filaments close to each other can move away horizontally or vertically, but after a long time, come back and perform damped oscillations while approaching the aligned configuration with almost touching filament ends. We confirm the attractive nature of the aligned configuration of very close semi-flexible sedimenting fibers, even if they are far away from each other.
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All authors Harish N. Mirajkar, Chandra Shekhar, Yevgen Melikhov, Piotr Zdybel, Maria L. Ekiel-Jezewska
Mesoscale and Nanoscale Physics
Emergent $\mathbb{Z}$-type topology in a quasi-one-dimensional extended QWZ model
Zebedeus F. Osseweijer, Lumen Eek and Cristiane Morais Smith
We investigate the emergence of zero-dimensional topological end states in nanoribbons described by the Qi-Wu-Zhang (QWZ) model and its extensions with longer-range couplings. While dimensional reduction from two to one dimension is often assumed to preserve the
symmetry classification of the parent system, here an additional
symmetry can emerge originating from the real-space geometry of the ribbon. This
symmetry acts as a
chiral symmetry, combining orbital and spatial transformations, and promotes the effective one-dimensional system from
symmetry class D to class BDI. We demonstrate that the existence of such a
symmetry depends both on the long and end termination of the ribbon and exhibits an even-odd effect with respect to ribbon width, revealing that the commonly studied rectangular ribbons constitute a special high-
symmetry case. For the conventional QWZ model, we derive analytic expressions for the topological phase boundaries of finite-width nanoribbons and characterize the resulting hybridization-gap phases through ($\mathbb{Z}_2 $) and winding-number invariants. We further show that extended QWZ models with longer-range couplings support phases with multiple topological end states and higher winding numbers. These phases arise through distinct mechanisms, including the hybridization of multiple edge modes inherited from higher-Chern-number bulk phases. Our results demonstrate that both long and end termination can fundamentally alter the topological classification of confined Chern
insulators, highlighting the interplay between crystalline geometry, emergent
symmetries, and dimensional reduction.
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Strongly Correlated Electrons
Quantum Destabilization of Skyrmions in Centrosymmetric Frustrated Magnets
Amit Kumar and Kalpataru Pradhan
We investigate the role of the
spin quantum number $s$ on the stability of skyrmions in a $J_1-J_2-J_3$ centrosymmetric
quantum Heisenberg model on a square
lattice using the neural network
quantum states method. Our results reveal that the skyrmion stability $Q$ is severely degraded when transitioning from the semiclassical regime to the extreme
quantum limit ($s=1/2$), where it ultimately vanishes. We demonstrate that this destabilization is driven by
quantum longitudinal fluctuations, with $Q$ exhibiting a power-law decay as a function of the reciprocal
spin moment $1/s$. Notably, the extreme
quantum limit ($s=1/2$) deviates drastically from this scaling behavior, exhibiting distinct physics compared to larger
spin moments. Furthermore, we reveal the microscopic origin of this decay by establishing a quantitative correspondence between skyrmion stability,
entanglement, and local
spin magnitude: as the local second Rényi
entropy (an indicator of
entanglement) increases and the local
spin magnitude is suppressed, the skyrmion stability vanishes linearly. This regime marks a
quantum state where the skyrmion number $C$ remains as remanent
geometric feature of the
spin orientations, yet the skyrmion stability $Q$ vanishes due to the longitudinal suppression of the local
spin magnitude. Our findings suggest that classically robust skyrmion phases in frustrated
lattices are fundamentally restricted to high-
spin materials, indicating that a
spin moment must of at least $s = 3/2$ is required for the realization of stable, atomic-scale topological textures.
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Materials Science · Cross-listed from physics.chem-ph
Improving Jet A-1 Thermal-Oxidative Stability through Selective Removal of Unwanted Trace Species via 3.7 Å Chabazite Filtration
Morteza Roostaeinia, Ehsan Alborzi, Xue Yong et al. (+2 more)
The thermal stability of Jet A-1 fuel is strongly affected by trace heteroatomic species that promote thermal oxidative deposit formation, as well as antioxidant additives such as butylated hydroxytoluene, which preserve fuel stability. 3.7 Å chabazite is a tunable microporous adsorbent, but optimizing its composition requires balancing promoter removal against antioxidant loss. Here, we use density functional theory and ab initio molecular dynamics (AIMD) to evaluate this trade-off using two compositional descriptors: framework acidity (Si/Al $= 35$–$8$) and bimetallic substitution (Co, Mg, Zn) at fixed Al content. Lowering Si/Al strengthens adsorption of all species, including BHT, confirming an intrinsic selectivity penalty for acidity-only tuning. In contrast, bimetallic substitution introduces chemically selective behavior, strengthening uptake of specific promoters while either suppressing or enhancing antioxidant adsorption depending on dopant identity. AIMD simulations at 400 K further show that adsorption energy alone is insufficient to describe calculated trends, because molecular mobility inside chabazite can influence residence time and effective capture during fuel treatment. Analysis of the density of states and the participating wavefunctions reveals signatures that are consistent with dopant-dependent adsorption shifts. These results establish a unified adsorption–transport–electronic screening framework for selecting chabazite compositions that remove deposit promoters while preserving antioxidant functionality in Jet A-1 treatment.
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All authors Morteza Roostaeinia, Ehsan Alborzi, Xue Yong, Kyungwha Park, Vsevolod Ivanov