Article
Physics, Applied
Zhanpeng Sun, Zijun Qi, Kang Liang, Xiang Sun, Zhaofu Zhang, Lijie Li, Qijun Wang, Guoqing Zhang, Gai Wu, Wei Shen
Summary: Ga2O3 is a semiconductor with a wide range of crystal configurations that holds potential for various applications, particularly in power electronics and ultraviolet optoelectronics. A new interatomic potential based on neural networks has been developed for Ga2O3, offering the advantages of lower computational requirements compared to density functional theory while maintaining high accuracy in predicting the thermal conductivity of Ga2O3 polymorphs. It has been discovered that low-frequency phonons significantly contribute to thermal conductivity in Ga2O3, and factors such as low symmetry and high atomic number can negatively impact the material's thermal conductivity. This study proposes a scheme for accurately predicting Ga2O3's thermal conductivity and successfully achieves relatively accurate results for epsilon-Ga2O3, providing an atomic-scale perspective on the differences in thermal conductivity among alpha, beta, and epsilon-Ga2O3.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Chemical
Yuan Tao, Bowen Yan, Nana Zhang, Jianxin Zhao, Hao Zhang, Wei Chen, Daming Fan
Summary: This study investigates the effects of microwaves on the evaporation of glucose solutions through molecular dynamics simulations and experimental studies. The results show that microwaves do not affect water evaporation behavior and no superheating was observed. High-intensity microwaves enable rapid boiling and intensified film boiling, leading to the high efficiency of microwave vacuum evaporation.
JOURNAL OF FOOD ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Zheyong Fan, Zezhu Zeng, Cunzhi Zhang, Yanzhou Wang, Keke Song, Haikuan Dong, Yue Chen, Tapio Ala Nissila
Summary: In this research, a neuroevolution-potential framework for generating neural network-based machine-learning potentials trained with an evolutionary strategy is developed. The atomic environment descriptor is constructed using Chebyshev and Legendre polynomials. The NEP method, implemented in GPUMD package, achieves high computational speed and provides per-atom heat current information.
Article
Physics, Multidisciplinary
Tine Curk, Erik Luijten
Summary: Nanoparticles in solution acquire charge through surface groups, requiring the use of charge-regulating boundary conditions for proper description of electrostatic interactions. A hybrid Monte Carlo/molecular dynamics scheme is implemented to dynamically adjust charges of surface groups, qualitatively changing self-assembled structures. The conventional constant-charge approximation may be used under certain conditions, and the interplay between charge regulation and dielectric polarization is clarified.
PHYSICAL REVIEW LETTERS
(2021)
Article
Biochemistry & Molecular Biology
Dorota Kowalska, Joanna Dolzonek, Krzysztof Zamojc, Sergey A. Samsonov, Martyna Maszota-Zieleniak, Joanna Makowska, Piotr Stepnowski, Anna Bialk-Bielinska, Dariusz Wyrzykowski
Summary: Human serum albumin (HSA) plays a crucial role in binding low-molecular-weight compounds and facilitating their distribution in living organisms. This study investigates the impact of counter-ions, such as [B (CN)4]- and [C(CN)3]-, on the affinity of [IM1-12]+ towards HSA. Experimental methods and computational approaches are used to analyze protein-ligand interactions and the thermal stability of resulting complexes. The findings provide valuable insights into the presence of globular proteins and ionogenic compounds in the environment and living organisms.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Thermodynamics
Yoshitaka Ueki, Yukihiro Yamamoto, Taku Ohara, Masahiko Shibahara
Summary: This study investigates the energy transport mechanism of nanofluids by decomposing the effective thermal conductivity and focuses on the influence of liquid layering around nanoparticles. The results show that the local effective thermal conductivity of the nearest adsorption layer increases with improved nanoparticle wettability, but there is an upper limit. The local effective thermal conductivity of the liquid, excluding the adsorption layers, also increases with improved nanoparticle wettability, but the main contribution to the overall effective thermal conductivity comes from the change in the local effective thermal conductivity of the liquid, except for the adsorption layers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Biochemistry & Molecular Biology
Mojtaba Mortazavi, Masoud Torkzadeh-Mahani, Mehdi Rahimi, Mahmood Maleki, Safa Lotfi, Ali Riahi-Madvar
Summary: The impact of synonymous mutations on the thermostability of luciferase was investigated. It was found that synonymous mutations can slightly increase the thermal stability of the mutant enzyme, possibly by altering the translation rate and causing slight structural changes. The results suggest that thermostability mainly originates from hydrophobic interactions.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Chemistry, Physical
G. De Thomasis, A. Galante, G. Fioravanti, L. Ottaviano, M. Alecci, G. Profeta
Summary: We calculate the spin-lattice relaxation time of water in contact with graphene oxide using molecular dynamics simulations. The water-graphene oxide interaction is characterized by calculating the relaxation properties of bulk water and the contact angle, and comparing them with experimental data. The effect of graphene oxide on the dynamics and relaxation properties of water in different conditions and concentrations is investigated. Despite the diamagnetic nature of graphene oxide, the confined bilayers strongly affect the longitudinal relaxation properties of interfacial water due to hydrogen bonds with oxygen groups, making it a promising platform for studying water dynamics in confined geometries and a potential contrast-agent for MRI applications.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Oliver T. Unke, Stefan Chmiela, Michael Gastegger, Kristof T. Schuett, Huziel E. Sauceda, Klaus-Robert Mueller
Summary: SpookyNet is a deep neural network that addresses the issue of electronic degrees of freedom and nonlocality typically ignored in machine-learned force fields. By incorporating chemically meaningful inductive biases and analytical corrections into the network architecture, SpookyNet can improve performance in quantum chemistry and fill important gaps in machine learning models.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
N. Gao, Z. W. Yao, G. H. Lu, H. Q. Deng, F. Gao
Summary: The study found a new diffusion mechanism for <100> interstitial dislocation loops in BCC iron using self-adaptive accelerated molecular dynamics, which represents a significant step towards understanding the mechanical behavior and microstructure evolution of the material.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Hang Yuan, Zhanjun Wang, Yanyun Zhang, Cong Wang
Summary: Partially substituting MnO with MgO shows potential in improving the overall performance of SiO2-MnO-MgO-B2O3 fluxes for submerged arc welding. However, challenges remain in terms of structural and physical property variations due to limitations in experimental techniques. This study investigates the flux structure and thermophysical properties through molecular dynamics simulations, revealing the depolymerization of the bulk network and decreased viscosity and thermal conductivity when MgO is replaced by MnO. The findings also shed light on the interaction between MnO and MgO in the flux structure and provide insights into the underlying molecular mechanisms.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Physics, Applied
Jixiong He, Jun Liu
Summary: This study investigates the effects of anharmonicity on phonon transport in strongly anharmonic crystals at finite temperatures and proposes a more robust fitting strategy, SSFM, to extract phonon lifetimes. SSFM alleviates the need for accurate temperature-dependent eigenvectors, making it suitable for analyzing strongly anharmonic crystals at high temperatures.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Dominik Sidler, Michael Ruggenthaler, Christian Schaefer, Enrico Ronca, Angel Rubio
Summary: This article provides a brief introduction to the theoretical complexity of polaritonic chemistry and emphasizes the importance of ab initio methods. It proposes novel ideas and research avenues regarding quantum collectivity and resonance phenomena in reaction rates under vibrational strong coupling. A computationally efficient Langevin framework based on quantum electrodynamical density-functional theory is also suggested, revealing cavity-induced non-equilibrium nuclear dynamics. Overall, the latest ab initio results suggest a paradigmatic shift in the understanding of ground-state chemical reactions under vibrational strong coupling.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Polymer Science
Victor M. Nazarychev, Sergey V. Lyulin
Summary: In recent decades, there has been a growing interest in improving the thermal conductivity of polymers for the development of new thermal interface materials (TIM) for electronic and electrical devices. In this study, the effects of uniaxial deformation on the thermal conductivity of thermoplastic polyimides were examined using atomistic computer simulations. The results showed that the thermal conductivity coefficient is anisotropic in different directions and significantly increases in the direction parallel to the deformation.
Article
Chemistry, Multidisciplinary
Anastassia Rissanou, Apostolos Konstantinou, Kostas Karatasos
Summary: Fully atomistic molecular dynamics simulations were conducted to investigate the effects of polymer size and composition on the morphology, energetics, and dynamics of graphene oxide (GO)-branched poly(ethyleneimine) (BPEI) hydrated mixtures. Results showed that the presence of cationic polymers hindered the formation of stacked GO conformations, leading to a disordered porous structure. Smaller polymers were more efficient at separating GO flakes. The interaction between the two components was found to be more favorable at an optimal composition, resulting in more stable structures.
Article
Chemistry, Multidisciplinary
Timothy D. Brown, Stephanie M. Bohaichuk, Mahnaz Islam, Suhas Kumar, Eric Pop, R. Stanley Williams
Summary: This study presents a model of VO2/SiN Mott threshold switches constructed using the principle of local activity. The model is refined to measurable material properties by considering a minimal set of quasistatic and dynamic electrical and thermal data. It accurately predicts electrical and thermal conductivities and capacitances, as well as locally active dynamics.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Su-in Yi, Santi Prasad Rath, T. Deepak, T. Venkatesan, Navakanta Bhat, Sreebrata Goswami, R. Stanley Williams, Sreetosh Goswami
Summary: A reliable and robust platform for in-memory computing using molecular materials is realized through the use of molecular switching elements with multiple non-monotonic and deterministic transitions. Experimental demonstrations and simulations show the potential of molecular materials in terms of reducing device count and computational steps, and achieving high reliability and performance in memory computing.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Anil Korkmaz, Gianluca Zoppo, Francesco Marrone, Su-In Yi, R. Stanley Williams, Fernando Corinto, Samuel Palermo
Summary: In this study, an analog circuit is proposed to accelerate the Power Iteration algorithm, which includes current-mode termination for the memristor crossbars and a normalization circuit. The performance of the system is demonstrated by computing different spectral centralities and comparing the results to conventional digital computers. Significant energy savings are observed while maintaining competitive accuracy.
IEEE JOURNAL ON EMERGING AND SELECTED TOPICS IN CIRCUITS AND SYSTEMS
(2023)
Article
Engineering, Electrical & Electronic
Su-in Yi, Jack D. Kendall, R. Stanley Williams, Suhas Kumar
Summary: This article reports on a training method using activity-difference-based training on co-designed analogue memristor crossbars. It treats network parameters as a constrained optimization problem and numerically calculates local gradients using behavioral differences. The trained neural networks can classify Braille words with high accuracy.
NATURE ELECTRONICS
(2023)
Article
Chemistry, Multidisciplinary
Dawei Gao, Rahul Shenoy, Suin Yi, Jungmin Lee, Mingjie Xu, Zixuan Rong, Atharva Deo, Dhruva Nathan, Jian-Guo Zheng, R. Stanley Williams, Yong Chen
Summary: This research presents a crossbar circuit of synaptic resistors (synstors) that can process signals and learn concurrently in real time. The synstor circuit outperforms an ANN running on computers in terms of learning speed, performance, power consumption, and adaptability to changing environments, and can fly drones to a target position faster than human controllers without prior training.
ADVANCED MATERIALS
(2023)
Article
Physics, Condensed Matter
C. J. Huggins, S. E. Savel'ev, A. G. Balanov, A. M. Zagoskin
Summary: Demonstration of the experimental feasibility and quantum effects of quantum behavior through the use of superposition of quantum states.
EUROPEAN PHYSICAL JOURNAL B
(2023)
Article
Physics, Applied
P. Navez, A. G. Balanov, S. E. Savel'ev, A. M. Zagoskin
Summary: By using the formalism of quantum electrodynamics, we have developed a comprehensive theoretical framework to describe the interaction between single microwave photons and an array of superconducting transmon qubits in a waveguide cavity resonator. Our analysis reveals the effects of microwave photons on the array's response to a weak probe signal, showing that high quality factor cavities provide better spectral resolution, while moderate quality factor cavities offer better sensitivity for single-photon detection. Surprisingly, our results demonstrate that even a single qubit in a cavity can detect a single-photon signal under realistic system parameters. We also discuss the influence of quantum properties and electrodynamical properties on the response of qubit arrays. This study provides an efficient theoretical foundation for the development and design of quantum devices with qubit arrays, especially those using cavities with explicit expressions for transmission or reflection.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Stephanie M. Bohaichuk, Suhas Kumar, Mahnaz Islam, Miguel Munoz Rojo, R. Stanley Williams, Gregory Pitner, Jaewoo Jeong, Mahesh G. Samant, Stuart S. P. Parkin, Eric Pop
Summary: Oscillatory devices are important in biomimetic neuronal spiking computing systems, but understanding their time scales is challenging due to the influence of external circuitry. In this study, we demonstrate the challenges using a sub-100-nm VO2 Mott oscillator with a nanogap cut in a metallic carbon nanotube electrode. Despite its nanoscale thermal volume, external parasitics result in orders-of-magnitude slower dynamics. We discuss methods for determining when measurements are dominated by extrinsic factors and the conditions for observing intrinsic oscillation frequencies.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Applied
D. P. Patnaik, Y. Ushakov, Z. Zhou, P. Borisov, M. D. Cropper, U. W. Wijayantha, A. G. Balanov, S. E. Savel'ev
Summary: This study found that varying temperature can efficiently control the states and charges transport of memristors, even allowing for reset when it cannot be done by varying the applied voltage.
PHYSICAL REVIEW APPLIED
(2023)
Editorial Material
Chemistry, Multidisciplinary
J. Joshua Yang, Julie Grollier, R. Stanley Williams, Ru Huang
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
D. P. Pattnaik, C. Andrews, M. D. Cropper, A. Gabbitas, A. G. Balanov, S. Savel'ev, P. Borisov
Summary: Gamma radiation has been found to have a novel effect on diffusive memristors based on metallic silver nanoparticles and a silica dielectric matrix. The irradiated memristors and artificial neurons made from them exhibit improved performance in terms of resistive switching and spiking frequencies. Nanoinclusions of reduced silicon distributed across the silica layer are proposed to be the backbone for the formation of conductive filaments.
Proceedings Paper
Computer Science, Hardware & Architecture
G. Zoppo, F. Marrone, F. Corinto, A. Korkmaz, Su-In Yi, S. Palermo, R. S. Williams
Summary: This article describes the impact of wire resistance on the accuracy of a system during matrix-vector multiplication and provides a mathematical description to evaluate this effect. The main contribution of the research is to help us understand and address the potential negative effects of wire resistance on computing system performance.
2022 19TH INTERNATIONAL SOC DESIGN CONFERENCE (ISOCC)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Su-In Yi, Suhas Kumar, R. Stanley Williams
Summary: In this study, we demonstrate through simulations that transient perturbations introduced by non-zero diagonal elements in a Hopfield network can significantly improve graph optimization efficiency, and we have simulated and controlled the nonidealities in memristor arrays.
2022 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS 22)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
T. Venkatesan, Sreebrata Goswami, R. Stanley Williams, Sreetosh Goswami
Summary: By mapping logic complexities onto molecular redox transitions, decision trees are embedded in nanoscale memristive elements. These molecular elements offer a substantial advancement in stateful in-memory computing technology with robustness and deterministic switching events.
2022 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS 22)
(2022)
Article
Materials Science, Multidisciplinary
Samane Kalhor, Sergey Savel'ev, Kaveh Delfanazari
Summary: The study describes the engineering of ultrastrong light-matter interactions in a deeply subwavelength microcavity array. By altering the width of the microcavities, the cross-behavior of ultrastrong coupling can be achieved. The research shows that the normalized Rabi splitting is independent of temperature in the BSCCO superconducting regime.
