Article
Chemistry, Physical
Yuzhong Yao, William M. Freund, Jie Zhang, Wei Kong
Summary: This study examines the volume averaging effect of nonlinear processes in focused laser fields and its impact on experimental results. It concludes that careful modeling and intensity selective scans are necessary to avoid erroneous fitting exponents and reveal detailed saturation effects in multi-photon processes. Experimental measurements using a nanosecond laser show remarkable agreements between theoretical and experimental intensity dependence values.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Meng Zhang, Toshiaki Ando, Atsushi Iwasaki, Lidong Wang, Sho Koh, Kaoru Yamanouchi
Summary: The double ionization and ultrafast hydrogen migration of methylamine induced by a few-cycle intense near-infrared laser pulse were investigated using the coincidence momentum imaging method. By analyzing the kinetic energy release distributions and the angular distributions of the fragment ions, the singlet and triplet decomposition channels of CH3NH22+ were identified. The ultrafast hydrogen migration in CH3NH2+ was found to occur within approximately 30 fs based on pump-probe measurements.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Yuzhong Yao, Jie Zhang, William M. Freund, Steven Tran, Wei Kong
Summary: We present experimental measurements of cluster sizes formed by supersonic expansion of two different species based on the time-of-flight principle. Argon clusters containing aromatic molecules were ionized with 266 nm wavelength at a low laser intensity. An increased sensitivity of a microchannel plate detector was achieved by accelerating the heavy cluster ions with high voltage. Our measurements of argon clusters, neat molecular clusters, and molecular-Ar clusters, are qualitatively in agreement with predictions from the scaling law, but the fitting exponents for the dependence of cluster sizes on both the stagnation pressure and temperature are different.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Yuzhong Yao, Jie Zhang, Rahul Pandey, Di Wu, Wei Kong, Lan Xue
Summary: The experimental results showed that the relative abundance of Ar+ in the mass spectra of argon clusters increases significantly with increasing laser intensity, while the distribution of MCAIs remains constant. Additionally, the arrival time width of Ar+ increases with laser intensity, in contrast to the MCAIs which exhibit a constant width. These findings indicate the need for further theoretical investigations into the laser-matter interactions in this regime.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Multidisciplinary
Camila Bacellar, Adam S. Chatterley, Florian Lackner, C. D. Pemmaraju, Rico Mayro P. Tanyag, Deepak Verma, Charles Bernando, Sean M. O. O'Connell, Maximilian Bucher, Ken R. Ferguson, Tais Gorkhover, Ryan N. Coffee, Giacomo Coslovich, Dipanwita Ray, Timur Osipov, Daniel M. Neumark, Christoph Bostedt, Andrey F. Vilesov, Oliver Gessner
Summary: Strong-field ionization of nanoscale clusters provides a unique way to study the complex dynamics of high-density plasmas. By using femtosecond time-resolved x-ray coherent diffractive imaging, the plasma dynamics induced by near-infrared laser in helium droplets with 600 nm diameter were investigated. The observations reveal the establishment of an anisotropic surface region within 100 fs and the subsequent contraction of the dense plasma core at different rates along and perpendicular to the laser polarization.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Medicinal
Shiru Wu, Xiaowei Yang, Xun Zhao, Zhipu Li, Min Lu, Xiaoji Xie, Jiaxu Yan
Summary: Force fields are crucial in molecular simulations and have applications in various fields. Machine learning force fields, constructed using machine learning techniques, offer advantages such as high accuracy and low cost compared to traditional force fields.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Nanoscience & Nanotechnology
Jiahua Cai, Sai Chen, Chunyan Geng, Jianghao Li, Baogang Quan, Xiaojun Wu
Summary: We investigate the nonlinear modulation dynamics of a THz-nano metasurface on silicon substrates using a time-resolved strong-field THz-pump THz-probe (TPTP) technique. The self-modulation phenomenon with a frequency shift of about 50 GHz is achieved by switching the THz field strength. This phenomenon is attributed to the impact ionization (IMI) of the silicon substrate under the excitation of strong THz fields in nano-gaps.
Article
Optics
A. J. Howard, C. Cheng, R. Forbes, G. A. McCracken, W. H. Mills, V Makhija, M. Spanner, T. Weinacht, P. H. Bucksbaum
Summary: Polyatomic molecules in strong laser fields exhibit substantial nuclear motion within tens of femtoseconds. Short pulses show minimal internuclear motion before shutting off, while rapid motion occurs during double ionization in longer pulses. The results suggest a simple tunnel ionization model can help interpret the observed motion.
Article
Optics
Yang Liu, Shen He, Longxing Zhou, Qi Chen, Yiwen Zhao, Tian Sun, Xingchen Shen, Tao Yu, Hang Lv, Haifeng Xu
Summary: This study experimentally investigates the photoionization and dissociation process of vinyl bromide molecules in strong femtosecond laser fields. The ion yields' dependence on laser intensity and polarization is examined and compared between different wavelength laser fields. Information on the kinetic energy releases from Coulomb explosion and the angular distributions of different fragment ions is obtained. The mechanisms of strong-field ionization/dissociation of vinyl bromide in different laser fields are discussed based on the experimental findings.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
H. Bernhard Schlegel, Paul Hoerner, Wen Li
Summary: This study investigates the coherent superposition of the X and A cations in neutral iodoacetylene through strong field ionization, and explores the orbital and angular dependence in the generation of cations and dications. It is found that the frequency of charge oscillation depends on the energy separation between the X and A states, while the ionization rates are affected by the polarization direction, carrier envelope phase, and initial phase of the superposition.
FRONTIERS IN CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Botong Liu, Yan Yang
Summary: We experimentally demonstrate the dissociative photoionization of CHBrCl2 molecules in a femtosecond laser field. The low kinetic energy components are from the dissociative ionization process of single-charged molecular ions. The angular distribution of fragment Cl+ ions can be attributed to the features of dissociative state and molecular configuration, while that of Br+ ions results from the electronic wave-packet evolution and combination of the multi-dissociation processes. The high kinetic energy components are from the Coulomb explosion of multi-charged molecular ions, and the error of the C-Br distance involved in the Coulomb explosion can be explained by the movement of the effective charge center of the polyatomic molecule.
APPLIED SCIENCES-BASEL
(2022)
Article
Physics, Multidisciplinary
Xiangxu Mu, Ming Zhang, Hanwei Yang, Min Li, Keyu Guo, Zijian Lu, Jiechao Feng, Haitan Xu, Song Bin Zhang, Zheng Li
Summary: This study investigates the population dynamics after strong field molecular photoionization, revealing that the mechanisms of post-ionization population redistribution (PPRM) in the ion can be classified and differentiated based on angle-resolved kinetic energy release (KER) spectra. The imprints of PPRM in the KER spectra can be used to determine the branching ratio of population exchange pathways of different orders, by exploiting the pump-intensity-dependent variation of the spectra.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Optics
Ji-Cai Liu, Viktoriia Savchenko, Victor Kimberg, Michael Odelius, Faris Gel'mukhanov
Summary: Theoretical studies on X-ray absorption and core-ionization spectra of molecules pumped by two coherent infrared pulses with different polarizations have shown a sensitivity to the vibrational profile of X-ray probe spectra. The polarization dependence observed is qualitatively different for X-ray absorption and X-ray photoelectron spectra. This technique can be used to select differences in Franck-Condon distributions and study molecular rotation dynamics.
Article
Optics
Arnab Sen, S. Mandal, Sanket Sen, Bhas Bapat, R. Gopal, V Sharma
Summary: In this study, we investigated the fragmentation of multiply charged CH3I ions induced by moderately intense ultrashort laser fields. The results show an increase in fragment yield with longer pulse durations. Analysis based on theoretical models suggests that enhanced ionization is a result of rearrangement of molecular orbitals leading to increased resonance multiorbital coupling at critical distances.
Article
Chemistry, Physical
Stuart W. Crane, Jason W. L. Lee, Michael N. R. Ashfold
Summary: Multi-mass velocity map imaging studies and covariance map image analysis were used to investigate the dissociation dynamics of CF3IZ+ cations formed by near infrared strong field ionization. Several highly charged parent cations with charges ranging from 1 to at least 5 were studied, revealing the formation of various charged fragments and dissociation pathways.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Computer Science, Interdisciplinary Applications
P. M. Dinh, M. Vincendon, F. Coppens, E. Suraud, P-G Reinhard
Summary: This paper introduces QDD, a code package for simulating the dynamics of electrons and ions under external electromagnetic fields, considering electron emission and dissipative dynamics induced by electron-electron collisions. The code is based on Time-Dependent Density Functional Theory (TDDFT) and Self-Interaction Correction (SIC), allowing tracking of dissipative dynamics induced by dynamical correlations.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
S. Malbrunot-Ettenauer, S. Kaufmann, S. Bacca, C. Barbieri, J. Billowes, M. L. Bissell, K. Blaum, B. Cheal, T. Duguet, R. F. Garcia Ruiz, W. Gins, C. Gorges, G. Hagen, H. Heylen, J. D. Holt, G. R. Jansen, A. Kanellakopoulos, M. Kortelainen, T. Miyagi, P. Navratil, W. Nazarewicz, R. Neugart, G. Neyens, W. Noertershauser, S. J. Novario, T. Papenbrock, T. Ratajczyk, P. G. Reinhard, L. Rodriguez, R. Sanchez, S. Sailer, A. Schwenk, J. Simonis, V Soma, S. R. Stroberg, L. Wehner, C. Wraith, L. Xie, Z. Y. Xu, X. F. Yang, D. T. Yordanov
Summary: Collinear laser spectroscopy was used to study the nuclear charge radii of nickel isotopes. Three ab initio methods were compared, with agreement in differential radii but only the NNLOsat method showing consistent absolute radii. The Skyrme functional SV-min was found to match experimental results more closely in nuclear density functional theory.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Joonseok Hur, Diana P. L. Aude Craik, Ian Counts, Eugene Knyazev, Luke Caldwell, Calvin Leung, Swadha Pandey, Julian C. Berengut, Amy Geddes, Witold Nazarewicz, Paul-Gerhard Reinhard, Akio Kawasaki, Honggi Jeon, Wonho Jhe, Vladan Vuletic
Summary: Using optical precision spectroscopy to test isotope shifts, this study explores new forces and basic properties of atomic nuclei. The data reveal nonlinearity in the King plot and a second distinct source of nonlinearity, trends that can be explained through nuclear density functional theory calculations.
PHYSICAL REVIEW LETTERS
(2022)
Article
Computer Science, Interdisciplinary Applications
Mengzhi Chen, Tong Li, Bastian Schuetrumpf, Paul-Gerhard Reinhard, Witold Nazarewicz
Summary: The HFBFFT solver, based on Sky3D code, is developed to study the weakly bound nuclei affected by the quasiparticle continuum space. It solves the underlying equations directly in the canonical basis using fast Fourier transform, and implements measures like soft energy cutoff and pairing annealing to address the problems encountered in the pairing collapse. The accuracy and performance of HFBFFT have been tested and compared with other HFB codes for various nuclei.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
P-G Reinhard, P. M. Dinh, D. Dundas, E. Suraud, M. Vincendon
Summary: Recent investigations have revealed that molecules exhibit a dipole instability after being irradiated with a short and strong XUV pulse. By instantaneously generating a hole in one of the occupied states of the system, we analyzed the mechanism of the dipole instability and its dependence on the system, the state of the hole, and the amount of depletion. Furthermore, we briefly discussed the mechanism of generating a coherent photon field in analogy to the dipole instability observed.
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2023)
Article
Physics, Multidisciplinary
Paul-Gerhard Reinhard, Xavier Roca-Maza, Witold Nazarewicz
Summary: The recent experimental determination of the parity violating asymmetry APV in 48Ca and 208Pb at Jefferson Lab is important for understanding the arrangement of neutrons and protons inside atomic nuclei. To assess the impact of these measurements, a rigorous theoretical investigation and evaluation of associated uncertainties were conducted. The study concluded that accurate description of APV in 48Ca and 208Pb cannot be achieved by their models.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
D. Hughes, D. Dundas, P. M. Dinh, M. Vincendon, P. -G. Reinhard, E. Suraud
Summary: We study the response of small covalent molecules to XUV laser pulses and discover the development of a dipole instability well after the pulse has died out. This instability is found to be robust against ionic motion and different laser characteristics. Experimental verification of this phenomenon is proposed.
EUROPEAN PHYSICAL JOURNAL D
(2023)
Correction
Physics, Nuclear
Paul -Gerhard Reinhard, Witold Nazarewicz
Article
Optics
P. -G. Reinhard, D. Dundas, P. M. Dinh, M. Vincendon, E. Suraud
Summary: We investigate the depletion of deep-lying single-electron states in the N2 dimer under the influence of very short extreme-ultraviolet (XUV) pulses. We find a marked occupation inversion for a certain window of XUV energies around 50 eV, and this occupation inversion drives a dipole instability, resulting in a spontaneous reappearance of the dipole signal long after the laser pulse is over.
Article
Physics, Nuclear
P. Alexa, M. Abolghasem, G. Thiamova, D. Bonatsos, T. R. Rodriguez, P-G Reinhard
Summary: The study investigates the spherical-to-deformed phase transition in cerium isotopes using macroscopic algebraic collective model and two microscopic approaches. The results suggest the presence of octupole softness and shape coexistence in 146Ce and 148Ce.
Article
Physics, Nuclear
Paul-Gerhard Reinhard, Witold Nazarewicz
Summary: In this study, the impact of local shell effects on the statistical correlations between quadrupole deformations and charge radii in Er, Yb, and Hf isotopes is investigated. The results show that the correlations between nuclear deformations and charge radii are affected by the underlying shell structure, and the correlation range is rather short even for well deformed nuclei.
Article
Physics, Nuclear
N. Lyutorovich, V. Tselyaev, J. Speth, G. Martinez-Pinedo, K. Langanke, P. -G. Reinhard
Summary: This study investigates high-spin states in Pb-208 using a self-consistent phonon-coupling model and finds that the standard Skyrme functionals provide a good description of these states.
Article
Physics, Nuclear
Paul-Gerhard Reinhard, Witold Nazarewicz
Summary: Differences in charge radii of mirror nuclei are suggested to contain information on the slope of the symmetry energy. However, statistical correlation analysis shows that the difference in charge radii, Delta R-ch(mir), is an inferior indicator compared to other observables such as neutron skin or electric dipole polarizability. The presence of pairing correlations and low-lying proton continuum affects Delta R-ch(mir). Therefore, the precise data on mirror charge radii cannot provide a stringent constraint on the slope of the symmetry energy L.
Article
Physics, Nuclear
Markus Kortelainen, Zhonghao Sun, Gaute Hagen, Witold Nazarewicz, Thomas Papenbrock, Paul-Gerhard Reinhard
Summary: The radii of nuclear charge distributions provide information about the forces inside the atomic nucleus. The global behavior of nuclear charge radii is determined by nuclear matter properties, while the local trends are influenced by the motion of protons and neutrons. By analyzing even-even nuclei from calcium to zinc, two advanced theories based on nuclear interactions reveal a universal pattern and demonstrate the impact of nuclear properties and shell structure on the differential charge radii.
Article
Physics, Nuclear
P. Adsley, V. O. Nesterenko, M. Kimura, L. M. Donaldson, R. Neveling, J. W. Brummer, D. G. Jenkins, N. Y. Kheswa, J. Kvasil, K. C. W. Li, D. J. Marin-Lambarri, Z. Mabika, P. Papka, L. Pellegri, V Pesudo, B. Rebeiro, P-G Reinhard, F. D. Smit, W. Yahia-Cherif
Summary: The study investigates the isoscalar dipole and monopole strengths in three light nuclei with different properties and analyzes clustering and vorticity manifestations. Experimental and theoretical approaches were used to observe and compare different transitions in these nuclei, leading to conclusions about the presence and characteristics of cluster and mean-field phenomena. Results suggest a correspondence between observed and theoretical states, demonstrating the combination of cluster and mean-field properties in low-energy isoscalar dipole states.
Correction
Materials Science, Multidisciplinary
A. D. Boccardo, M. Tong, S. B. Leen, D. Tourret, J. Segurado
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Tao Li, Qing Hou, Jie-chao Cui, Jia-hui Yang, Ben Xu, Min Li, Jun Wang, Bao-qin Fu
Summary: This study investigates the thermal and defect properties of AlN using molecular dynamics simulation, and proposes a new method for selecting interatomic potentials, developing a new model. The developed model demonstrates high computational accuracy, providing an important tool for modeling thermal transport and defect evolution in AlN-based devices.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Shin-Pon Ju, Chao-Chuan Huang, Hsing-Yin Chen
Summary: Amorphous boron nitride (a-BN) is a promising ultralow-dielectric-constant material for interconnect isolation in integrated circuits. This study establishes a deep learning potential (DLP) for different forms of boron nitride and uses molecular dynamics simulations to investigate the mechanical behaviors of a-BN. The results reveal the structure-property relationships of a-BN, providing useful insights for integrating it in device applications.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
M. Salman, S. Schmauder
Summary: Shape memory polymer foams (SMPFs) are lightweight cellular materials that can recover their undeformed shape through external stimulation. Reinforcing the material with nano-clay filler improves its physical properties. Multiscale modeling techniques can be used to study the thermomechanical response of SMPFs and show good agreement with experimental results.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Laura Gueci, Francesco Ferrante, Marco Bertini, Chiara Nania, Dario Duca
Summary: This study investigates the acidity of 30 Bronsted sites in the beta-zeolite framework and compares three computational methods. The results show a wide range of deprotonation energy values, and the proposed best method provides accurate calculations.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
K. A. Lopes Lima, L. A. Ribeiro Junior
Summary: Advancements in nanomaterial synthesis and characterization have led to the discovery of new carbon allotropes, including biphenylene network (BPN). The study finds that BPN lattices with a single-atom vacancy exhibit higher CO2 adsorption energies than pristine BPN. Unlike other 2D carbon allotropes, BPN does not exhibit precise CO2 sensing and selectivity by altering its band structure configuration.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Jay Kumar Sharma, Arpita Dhamija, Anand Pal, Jagdish Kumar
Summary: In this study, the quaternary Heusler alloys LiAEFeSb were investigated for their crystal structure, electronic properties, and magnetic behavior. Density functional theory calculations revealed that LiSrFeSb and LiBaFeSb exhibit half-metallic band structure and 100% spin polarization, making them excellent choices for spintronic applications.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Roman A. Eremin, Innokentiy S. Humonen, Alexey A. Kazakov, Vladimir D. Lazarev, Anatoly P. Pushkarev, Semen A. Budennyy
Summary: Computational modeling of disordered crystal structures is essential for studying composition-structure-property relations. In this work, the effects of Cd and Zn substitutions on the structural stability of CsPbI3 were investigated using DFT calculations and GNN models. The study achieved accurate energy predictions for structures with high substitution contents, and the impact of data subsampling on prediction quality was comprehensively studied. Transfer learning routines were also tested, providing new perspectives for data-driven research of disordered materials.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Zhixin Sun, Hang Dong, Yaohui Yin, Ai Wang, Zhen Fan, Guangyong Jin, Chao Xin
Summary: In this study, the crystal structure, electronic structure, and optical properties of KH2PO4: KDP crystals under different pressures were investigated using the generalized gradient approximate. It was found that high pressure caused a phase transition in KDP and greatly increased the band gap. The results suggest that high pressure enhances the compactness of KDP and improves the laser damage threshold.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Tingting Yu
Summary: This study presents atomistic simulations revealing that an increase in driving force may result in slower grain boundary movement and switches in the mode of grain boundary shear coupling migration. Shear coupling behavior is found to effectively alleviate stress and holds potential for stress relaxation and microstructure manipulation in materials.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Y. Zhang, X. Q. Deng, Q. Jing, Z. S. Zhang
Summary: The electronic properties of C2N/antimonene van der Waals heterostructure are investigated using density functional theory. The results show that by applying horizontal strain, vertical strain, electric field, and interlayer twist, the electronic structure can be adjusted. Additionally, the band alignment and energy states of the heterostructure can be significantly changed by applying vertical strain on the twisted structure. These findings are important for controlling the electronic properties of heterostructures.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Chad E. Junkermeier, Evan Larmand, Jean-Charles Morais, Jedediah Kobebel, Kat Lavarez, R. Martin Adra, Jirui Yang, Valeria Aparicio Diaz, Ricardo Paupitz, George Psofogiannakis
Summary: This study investigates the adsorption properties of carbon dioxide (CO2), methane (CH4), and dihydrogen (H2) in carbophenes functionalized with different groups. The results show that carbophenes can be promising adsorbents for these gases, with high adsorption energies and low desorption temperatures. The design and combination of functional groups can further enhance their adsorption performance.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Y. Borges, L. Huber, H. Zapolsky, R. Patte, G. Demange
Summary: Grain boundary structure is closely related to solute atom segregation, and machine learning can predict the segregation energy density. The study provides a fresh perspective on the relationship between grain boundary structure and segregation properties.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
M. R. Jones, L. T. W. Fey, I. J. Beyerlein
Summary: In this work, a three-dimensional ab-initio informed phase-field-dislocation dynamics model combined with Langevin dynamics is used to investigate glide mechanisms of edge and screw dislocations in Nb at finite temperatures. It is found that the screw dislocation changes its mode of glide at two distinct temperatures, which coincides with the thermal insensitivity and athermal behavior of Nb yield strengths.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Joshua A. Vita, Dallas R. Trinkle
Summary: This study introduces a new machine learning model framework that combines the simplicity of spline-based potentials with the flexibility of neural network architectures. The simplified version of the neural network potential can efficiently describe complex datasets and explore the boundary between classical and machine learning models. Using spline filters for encoding atomic environments results in interpretable embedding layers that can incorporate expected physical behaviors and improve interpretability through neural network modifications.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
