Article
Physics, Multidisciplinary
Yu-Hui Tang, Bao-Huei Huang, Min-Hsiung Tsai
Summary: This study applied an extended single Hamiltonian to investigate relativistic effects in atoms, including spin-orbit coupling and coupling with electric fields. The results show that spin-orbit coupling affects the behavior of electrons in metals and explain the Lorentzian broadening phenomenon at low temperatures.
CHINESE JOURNAL OF PHYSICS
(2022)
Review
Chemistry, Multidisciplinary
Xunhua Zhao, Zachary H. Levell, Saerom Yu, Yuanyue Liu
Summary: Two-dimensional electrocatalysts have gained significant attention in the field of renewable energy applications. However, there is still ongoing debate about the atomistic mechanisms involved. This review focuses on the atomistic mechanisms of common 2D electrocatalysts, including N doped graphene, single metal atoms in graphene, and transition metal dichalcogenides. The reactions studied encompass hydrogen evolution, oxygen evolution, oxygen reduction, and carbon dioxide reduction. The challenges and future directions to enhance the fundamental understanding of 2D electrocatalysts at the atomic level are also discussed.
Article
Physics, Applied
Ryoya Hiramatsu, Daisuke Miura, Akimasa Sakuma
Summary: In this study, we propose a method for calculating the Gilbert damping constants at finite temperature and apply it to two materials. By comparing our calculated results with experimental values, we observe a discrepancy, which reflects the characteristics of the torque correlation model.
APPLIED PHYSICS EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
G. Paradezhenko, D. Yudin, A. A. Pervishko
Summary: We systematically analyzed the finite-temperature magnetic properties of random alloys FexNi1-x with the face-centered-cubic structure across a wide range of concentrations. Utilizing the spin-polarized relativistic Korringa-Kohn-Rostoker method, we calculated the electronic structure of disordered iron-nickel alloys and explored how changes in composition affect magnetic moments and density of states. We investigated the dependence of the Curie temperature on Fe concentration using various techniques, with the dynamic spin-fluctuation theory showing the best fit to experimental results by explicitly accounting for spin fluctuations.
Article
Materials Science, Multidisciplinary
Alexander Fabian, Michael Czerner, Christian Heiliger, Hugo Rossignol, Ming-Hung Wu, Martin Gradhand
Summary: This study focuses on the calculation of spin accumulation at the surface of a thin metallic layer and makes quantitative predictions for different materials. By comparing semiclassical and fully quantum mechanical methods, it is found that the two methods agree well in the limit of the relaxation time approximation, with deviations attributed to the complexity of Fermi surfaces. Results are compared with experimental values, showing good agreement in the trend across the considered elements.
Article
Materials Science, Multidisciplinary
Davide Gambino, Johan Klarbring, Bjorn Alling
Summary: This work demonstrates the feasibility and accuracy of calculating phase stability in magnetic systems using ab initio methods and thermodynamic integration. By sampling the magnetic and vibrational phase space with coupled atomistic spin dynamics-ab initio molecular dynamics simulations, energies and interatomic forces are calculated with density functional theory. The method is applied to calculate the phase stability of Fe at ambient pressure from 800 to 1800 K. The Gibbs free energy difference between fcc and bcc Fe is calculated with thermodynamic integration, and the error in transition temperature is below 150 K, with a difference of 5 meV/atom from the CALPHAD estimate. This work lays the foundation for first principles free energy calculations in magnetic materials with accuracy on the order of 1 meV/atom.
Article
Engineering, Mechanical
Adnan M. El Makdah, Kai Zhang, David E. Rival
Summary: Rotor moment of inertia significantly affects the performance of rotating systems, and a normalized inertia number (I*) is introduced to characterize the dynamic response of a generic-rotor system relative to flow inertia. Experiments in a towing tank facility show that rotors with lower I* produce higher power output during gusts. Increasing I* and decreasing flow inertia result in a smaller increase in power output.
JOURNAL OF FLUIDS AND STRUCTURES
(2021)
Article
Physics, Applied
Ramon Cuadrado, Richard F. L. Evans, Tetsuya Shoji, Masao Yano, Akira Kato, Masaaki Ito, Gino Hrkac, Thomas Schrefl, Roy W. Chantrell
Summary: This study investigates the effects of strain on the magnetocrystalline anisotropy energy and magnetic moments of Y2Fe14B bulk alloy using density functional theory in a relativistic form. The study reveals a significant variation in the site-resolved magnetic moments for different lattice expansions and highlights the influence of the c/a ratio on the magnetocrystalline anisotropy. However, the calculated variation coupled with thermodynamic spin fluctuations cannot explain the experimentally observed increase in total magnetic anisotropy, suggesting the presence of a different physical mechanism.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Multidisciplinary
Jinsoo Park, Jin-Jian Zhou, Yao Luo, Marco Bernardi
Summary: Developing a microscopic understanding of spin decoherence is crucial for advancing quantum technologies. In this study, the authors present a computational approach that unifies the modeling of two main sources of phonon-induced spin decoherence and enables accurate predictions of spin relaxation and precession in semiconductors. Their findings highlight the significant role of vertex correction in the electron spin dynamics in solids, providing insights for the development of spin-based quantum technologies.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Hongyu Wu, Ri He, Yi Lu, Zhicheng Zhong
Summary: Quantum effects of lattice vibration have a significant impact on the physical properties of condensed-matter systems. However, simulating realistic materials with a fully quantum-mechanical description remains challenging. In this study, a first-principles strategy combining a high-accuracy force field and quantum thermal bath method is proposed to account for quantum effects in molecular dynamics simulations. The efficiency and applicability of this strategy are demonstrated using the example of SrTiO3, highlighting its potential for studying quantum behavior in condensed-matter physics.
Article
Physics, Multidisciplinary
Sergiy Mankovsky, Svitlana Polesya, Hannah Lange, Markus Weissenhofer, Ulrich Nowak, Hubert Ebert
Summary: The transfer and control of angular momentum is crucial for spintronic applications. A scheme to calculate fully relativistic spin-lattice coupling parameters from first principles is presented, contributing to the understanding of angular momentum transfer between spin and lattice degrees of freedom.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Frank Freimuth, Stefan Bluegel, Yuriy Mokrousov
Summary: The study investigates the spin-orbit torques in strained PtMnSb and their dependence on strain, magnetization direction, and exchange correlation potential. It is found that higher-order terms show more sensitivity to strain and exchange correlation potential, while the total SOT is insensitive to the exchange correlation potential due to the small contribution of higher-order terms in comparison to the lowest-order terms.
Article
Chemistry, Physical
Sourav Mondal, Alessandro Lunghi
Summary: Paramagnetic defects in diamond and hexagonal boron nitride exhibit spin and optical properties that make them ideal for solid-state qubits. However, their coherence is limited by spin-phonon relaxation, and a complete understanding of this process is lacking. In this study, we use ab initio spin dynamics simulations to successfully reproduce the experimental temperature dependence of spin relaxation and coherence time. We find that low-frequency two-phonon modulations are responsible for spin relaxation and decoherence, and attribute the shorter coherence time to the vibrations in 2-dimensional materials. These findings provide insights into spin-phonon decoherence in solid-state qubits and facilitate the design of more efficient spin qubits.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Matic Poberznik, Gabriela Herrero-Saboya, Darko Makovec, Darja Lisjak, Layla Martin-Samos
Summary: Barium hexaferrite (BHF) is a ferrimagnet that grows as platelets at the nanoscale, showing uniaxial magnetic anisotropy. The surface morphology of BHF nanoplatelets varies depending on the preparation conditions. Using ab initio thermodynamics, we found that the most stable surface terminations of BHF are the hydroxylated oxygen-terminated surfaces (12k-O) under Ba-poor and low pH conditions, and the hydroxylated 2b surface under high pH and Ba-rich conditions.
APPLIED SURFACE SCIENCE
(2023)
Article
Physics, Applied
David E. Sommer, Scott T. Dunham
Summary: The diffusion of copper in CuInSe2 was investigated using thermodynamic and kinetic models based on density functional theory calculations. Stable off-stoichiometries dominated by either vacancy- or interstitial-mediated diffusion mechanisms were identified. The findings were used to develop a continuum reaction-diffusion model for simulating experimental depth profiles.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Sudipta Kundu, Satadeep Bhattacharjee, Seung-Cheol Lee, Manish Jain
Summary: This study introduces methods to describe the contribution of different orbitals to electron distribution and interactions at various atom centers. By projecting wave functions from plane-wave basis to localized Wannier orbital basis, it provides insights into bonding contributions and electron localization in different materials.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Souradip Guha, Ankan Mullick, Jatin Agrawal, Swetarekha Ram, Samir Ghui, Seung-Cheol Lee, Satadeep Bhattacharjee, Pawan Goyal
Summary: The number of published articles in the field of materials science is increasing rapidly each year, but the information in these articles needs to be manually extracted for further calculations. To address this issue, researchers have developed an automated tool, MatScIE, which can extract relevant information from material science literature and create a structured database for easier use in material simulations.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Engineering, Electrical & Electronic
Anup Kumar Mandia, Bhaskaran Muralidharan, Seung Cheol Lee, Satadeep Bhattacharjee
Summary: The study provides a detailed investigation of electronic transport in In0.52Al0.48As, extracting important parameters and showing characteristics of transient electronic transport and optimization strategies. Results indicate that transient effects significantly impact devices with shorter lengths and should be taken into consideration in device design.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Physics, Applied
Ajit Jena, Seung-Cheol Lee, Satadeep Bhattacharjee
Summary: By studying the impact of magnetism-induced on bismuth telluride in the doped system, it is found that the nonlinearity induced by magnetic moment can effectively reduce the lattice thermal conductivity; the variance of internal energy affects the thermal conductivity, however, the thermal conductivity varies for different configurations at the same doping level.
PHYSICAL REVIEW APPLIED
(2021)
Article
Chemistry, Physical
J. Fransson
Summary: This study investigates the charge and spin dynamics in chiral molecules after their immediate coupling to an external metallic reservoir. The research describes the induction of spin polarization in chiral structures as a response to charge dynamics. The dynamics show that chirality-induced spin selectivity is an excited state phenomenon that can be partially explained using a simplistic single-particle description in the transient regime, but in the stationary limit, electron correlations, such as electron-vibration interactions, are crucial in sustaining an intrinsic spin anisotropy that leads to a nonvanishing spin selectivity. Furthermore, the dynamics provide insight into enantiomer separation based on different acquired spin polarizations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Namitha Anna Koshi, Dharmapura H. K. Murthy, Sudip Chakraborty, Seung-Cheol Lee, Satadeep Bhattacharjee
Summary: Strontium titanate is widely used as a promising photocatalyst due to its unique band edge alignment. Enhancing the photocatalytic activity through the control of oxygen vacancy states and doping with p-block elements like aluminum can reduce charge trapping states in SrTiO3. Calculations based on density functional theory have shown the synergistic effect of doping with aluminum and iridium in improving the photocatalytic efficiency of SrTiO3.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Anupam K. Singh, Parul Devi, Ajit K. Jena, Ujjawal Modanwal, Seung-Cheol Lee, Satadeep Bhattacharjee, Boby Joseph, Sanjay Singh
Summary: Isostructural phase transition is observed in the biskyrmion host MnNiGa under pressure, accompanied by anisotropic compression behavior. The crystal structure changes with pressure while maintaining hexagonal symmetry.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Chemistry, Physical
Kishalay Das, Bidisha Samanta, Pawan Goyal, Seung-Cheol Lee, Satadeep Bhattacharjee, Niloy Ganguly
Summary: We present a deep-learning framework, CrysXPP, for rapid and accurate prediction of electronic, magnetic, and elastic properties of various materials. The framework intelligently designs an autoencoder, CrysAE, to capture important structural and chemical properties from a large amount of crystal graph data, achieving low prediction errors. Additionally, it includes a feature selector to interpret the model's predictions.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Physics, Applied
Swastik Sahoo, Abhinaba Sinha, Namitha Anna Koshi, Seung-Cheol Lee, Satadeep Bhattacharjee, Bhaskaran Muralidharan
Summary: The outstanding properties of graphene have paved the way for investigating other 2D-Xene materials, with silicene being the most promising due to its compatibility with current silicon fabrication technologies. Recent studies on silicene have revealed its useful electronic and mechanical properties. In this study, a theoretical model is used to investigate the piezoresistance effect of silicene in the nanoscale regime. The obtained results suggest that silicene can be used as an interconnect in flexible electronic devices and as a reference piezoresistor in strain sensors. This research will contribute to the exploration of flexible electronics applications in other 2D-Xene materials.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Satadeep Bhattacharjee
Summary: We propose a general rule for estimating the magnetic moments of Co2-based Heusler alloys, especially when doped with late transition metals. We introduce a descriptor that can characterize both pure Co2YZ compounds and the doped ones. Our machine-learning approach is more generic than the Slater-Pauling rule since it applies to any Co2YZ Heusler compounds, regardless of whether they are half-metals or not.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Chemistry, Physical
J. Fransson
Summary: Magnetic phenomena in chemistry and condensed matter physics are usually associated with low temperatures. However, recent experimental observations on supramolecular aggregates suggest a surprising increase in magnetic coercivity with increasing temperature and enhancement of the chiral-induced spin selectivity effect. A proposed mechanism for vibrationally stabilized magnetism, along with a theoretical model, can explain the qualitative aspects of these experimental findings. The proposal argues that anharmonic vibrations, which become more pronounced at higher temperatures, can stabilize and sustain magnetic states, particularly in structures without inversion and/or reflection symmetries, such as chiral molecules and crystals.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
J. Fransson
Summary: Magnetic phenomena in chemistry and condensed matter physics are typically associated with low temperatures. However, recent experimental observations on supramolecular aggregates suggest that the magnetic coercivity may increase with increasing temperature, and the chiral-induced spin selectivity effect may be enhanced. A proposed mechanism for vibrationally stabilized magnetism and a theoretical model are introduced to explain these findings, suggesting that anharmonic vibrations enable nuclear vibrations to stabilize and sustain magnetic states in structures without inversion and/or reflection symmetries, such as chiral molecules and crystals.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Anup Kumar Mandia, Namitha Anna Koshi, Bhaskaran Muralidharan, Seung-Cheol Lee, Satadeep Bhattacharjee
Summary: The study introduced a new method to calculate the Hall scattering factor, combined with density functional theory calculations, revealing significant variations of the Hall scattering factor in electron-doped Ti2CO2 at different temperatures and concentrations. The electrical transport was primarily influenced by piezoelectric scattering, acoustic scattering, and polar optical phonons, with the highlighted role of piezoelectric scattering in limiting the mobility of the material.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Gaurav K. Shukla, Ajit K. Jena, Nisha Shahi, K. K. Dubey, Indu Rajput, Sonali Baral, Kavita Yadav, K. Mukherjee, Archana Lakhani, Karel Carva, Seung-Cheol Lee, Satadeep Bhattacharjee, Sanjay Singh
Summary: In this study, the anomalous Hall effect (AHE) in the polycrystalline Co2FeAl Heusler compound was investigated using experimental and theoretical approaches. The analysis revealed a high degree of antisite disorder between Fe and Al atoms. The experimental anomalous Hall conductivity (AHC) was found to be 227 S/cm at 2 K, with an intrinsic contribution of 155 S/cm, showing nearly constant variation with temperature.
Article
Chemistry, Physical
Satadeep Bhattacharjee, Seung-Cheol Lee
Summary: This study discusses chemisorption on ferromagnetic and non-magnetic surfaces within the framework of the Newns-Anderson-Grimley model and the Stoner model of ferromagnetism. The adsorption energy on ferromagnetic surfaces is formulated in terms of changes in surface magnetic moments, showing a possible scaling relationship between adsorption energy and surface magnetic moments. A modified Stoner criterion is formulated for non-magnetic surfaces to discuss the conditions for the appearance of magnetism due to chemisorption on an otherwise non-magnetic surface.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
