Article
Optics
Juan P. Ruz-Cuen, Julio C. Gutierrez-Vega
Summary: The paper presents general solutions to the Schrodinger equation for a di-periodic potential, extending it from the standard sinusoidal potential. Two different approaches were used to solve the three-term Whittaker-Hill equation with the di-periodic potential, resulting in the determination of Floquet-Bloch eigenwaves and band structure. Additionally, it was found that the Ince functions can describe the Mathieu functions obtained with purely sinusoidal potentials.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
A. D. Chepelianskii, D. Papoular, D. Konstantinov, H. Bouchiat, K. Kono
Summary: The study identified different plasmon excitation modes in a two-dimensional electron system on the liquid helium surface, including chiral one-dimensional edge magnetoplasmons and delocalized magnetoplasmon modes. The presence of a homogeneous density gradient was found to lead to the formation of these modes in the same frequency range, with experimental confirmation of their existence. This prototype system demonstrates the coupling between a chiral one-dimensional mode and a single delocalized bulk mode, providing insights into the transport properties of topological materials with states of different dimensionality.
Article
Materials Science, Multidisciplinary
Wanwan Shi, Peiqing Tong
Summary: We study the effects of infinite-range interaction on the localization properties of one-dimensional disordered harmonic chains. It is found that the infinite-range interaction induces a gap between ω=0 and the excited frequency band for both mass and spring disordered models, and their gaps are both proportional to the interaction coefficient γ. The width of the excited frequency band of the mass model is also proportional to γ for larger γ, while that of the spring model is independent of γ. The localized properties of the modes in the spring model remain unchanged, while the low-frequency modes in the mass model change from extended to localized states.
Article
Physics, Fluids & Plasmas
F. Leyvraz
Summary: The study explores an exact combinatorial solution for a variant of the Marcus-Lushnikov model, providing a full probability distribution of all possible size distributions using Bell polynomials. The results show that the exact solution is accurate in some cases with certain reaction rate kernels, while discrepancies are found in others.
Article
Physics, Applied
Manh-Huong Phan, M. Tuan Trinh, Tatiana Eggers, Vijaysankar Kalappattil, Ken-ichi Uchida, Lilia M. Woods, Mauricio Terrones
Summary: This paper discusses the characteristics of 2D van der Waals magnetic semiconductors and their research in combination with light and the spin Seebeck effect, aiming to explore a new strategy for optical control of SSE and drive the development of spin-caloritronics research.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
Satoru Morita
Summary: This study focuses on the spread of disease and information in social and information networks, emphasizing the importance of understanding degree distribution and degree correlation in the spread phenomena. By introducing a simple method to incorporate degree correlation, the theoretical formulas for outbreak threshold and basic reproduction number are presented, clarifying the theoretical effect of degree correlation.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2021)
Article
Physics, Multidisciplinary
Rui Dilao, Nuno Teixeira
Summary: We propose a solvable biped walking model that is based on an inverted pendulum with two massless articulated legs. This model allows the robot to walk on uneven surfaces and inclined planes. The stride of the robot is achieved through the pendular motion of a standing leg and the articulated motion of a trailing leg. By controlling the opening angle between the legs and the time of each stride, the robot is able to walk on different surfaces. The model provides closed-form solutions and can simulate various types of biped motion. Optimization results for the speed of gaiting as a function of robot parameters have been derived.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Geosciences, Multidisciplinary
Weiqin Sun, Sina Sadeghzadeh, Jian Yang, Wenrui Wang, Jun Cui
Summary: The study found that in a sawtooth substorm, the wide injection breaks up into multiple injection boundaries or channels with a separation of 1-2 hours. By tracing energetic particles and the self-consistently computed electromagnetic field, the MLT locations of the channels can be inferred, showing correlation with auroral structures.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Physics, Multidisciplinary
Carolyn Zhang, Michael Levin
Summary: We propose an exactly solvable lattice model to study the deconfined quantum critical point (DQCP) in (1+1) dimensions, which occurs at the edge of a (2+1) dimensional bosonic symmetry protected topological (SPT) phase with 7L2 x 7L2 symmetry. The DQCP describes a transition between two gapped edges that break different 7L2 subgroups of the full 7L2 x 7L2 symmetry. This model provides an exact mapping between the SPT edge theory and a 7L4 spin chain, revealing the close relationship between DQCPs in this system and ordinary 7L4 symmetry breaking critical points.
PHYSICAL REVIEW LETTERS
(2023)
Article
Engineering, Industrial
Zebiao Feng, Jianjun Wang, Yizhong Ma, Yiliu Tu
Summary: In this paper, a new weighted robust design approach is proposed to address the model uncertainty from outliers in contaminated experimental data. The robust Gaussian process model is used to estimate relationship models, and an optimization scheme is built to find feasible optimization solutions. The proposed approach outperforms other methods by considering the model uncertainty from outliers.
INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH
(2021)
Article
Physics, Multidisciplinary
Pavel A. Nosov, Ivan M. Khaymovich, Andrey Kudlis, Vladimir E. Kravtsov
Summary: The accuracy of the forward scattering approximation for two-point Green's functions of the Anderson localization model on the Cayley tree is analyzed. The relationship between the moments of the Green's function and the largest eigenvalue of the linearized transfer-matrix equation is proved, and a new approximation for this eigenvalue is derived. It is shown that the FSA overestimates the probability of the Green's function being significantly larger than its typical value.
Article
Materials Science, Multidisciplinary
Shuohang Wu, Zi Cai
Summary: In this paper, the eigenstate properties of a quantum Hopfield model are studied using the exact diagonalization method. The spins in this model are organized into clusters by local permutational symmetry, with each cluster being treated as a large quantum spin interacting with others. It is found that this quantum Hopfield model, even without dissipation, is interesting as it represents quantum frustrated magnetism and quantum spin glass. It shows three distinct phases: a low-energy spin-glass phase at a low transverse field, a thermal paramagnetic phase at a high transverse field, and a nonthermal high-energy paramagnetic phase. The dynamics of the revival probability starting from a memory pattern in this closed quantum many-body model is also investigated.
Article
Mathematics, Applied
Stevo Stevic, Durhasan Turgut Tollu
Summary: We consider a two-dimensional nonlinear system of difference equations with given delays and parameters, and find its general solution in detail.
Article
Physics, Multidisciplinary
Yun-Hao Shi, Yu Liu, Yu-Ran Zhang, Zhongcheng Xiang, Kaixuan Huang, Tao Liu, Yong-Yi Wang, Jia-Chi Zhang, Cheng-Lin Deng, Gui-Han Liang, Zheng-Yang Mei, Hao Li, Tian-Ming Li, Wei-Guo Ma, Hao-Tian Liu, Chi-Tong Chen, Tong Liu, Ye Tian, Xiaohui Song, Kai Xu, Dongning Zheng, Franco Nori, Heng Fan
Summary: This study develops a one-dimensional 43-qubit superconducting quantum processor called Chuang-tzu, which is used to simulate and characterize emergent topological states. The quantum processor is capable of capturing important topological features of quantum systems, providing a new method for studying quantum topological systems in the NISQ era.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Yannick Schubert, Nicola Marzari, Edward Linscott
Summary: Koopmans spectral functionals, designed to predict spectroscopic properties, outperform their Kohn-Sham density-functional theory counterparts in accurately describing Hooke's atom across different confining potential strengths. This study contributes to a better understanding of the features and capabilities of Koopmans spectral functionals.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Pierre-Francois Loos, Pina Romaniello
Summary: This study investigates the application of the T-matrix approximation in strongly correlated systems and evaluates its static and dynamic schemes. The results suggest that the T-matrix-based formalism performs well in few-electron systems with low electron density.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Enzo Monino, Pierre-Francois Loos
Summary: By recasting the non-linear frequency-dependent GW quasiparticle equation into a linear eigenvalue problem, this study explains the occurrence of multiple solutions and unphysical discontinuities in various physical quantities computed within the GW approximation. The GW self-energy is treated as an effective Hamiltonian, which reveals the key signatures of strong correlation in the (N +/- 1)-electron states and their direct relation to the intruder state problem. A regularization procedure inspired by the similarity renormalization group is proposed to avoid these issues and accelerate the convergence of partially self-consistent GW calculations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Rudraditya Sarkar, Pierre-Francois Loos, Martial Boggio-Pasqua, Denis Jacquemin
Summary: This study compares the performance of multiconfigurational methods such as CASPT2 and NEVPT2 in calculating excited state energies, and finds that CASPT2 and NEVPT2 with IPEA shift provide relatively reliable results. The findings are generally applicable to different subgroups of transitions.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Fabris Kossoski, Yann Damour, Pierre-Francois Loos
Summary: This article presents a novel partitioning method for the Hilbert space, hierarchy configuration interaction (hCI), where the excitation degree and seniority number are combined in a single parameter. By surveying the dissociation of multiple molecular systems, it is found that hCI usually outperforms or at least matches excitation-based CI in overall performance.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Pierre-Francois Loos, Michael Seidl
Summary: Researchers have performed numerous approximate electronic structure calculations by analyzing the parametrizations of the uniform electron gas (UEG). Recent studies have shown that, in addition to the traditional infinite UEG, systems consisting of electrons confined to the surface of a sphere can form a new type of customizable UEG. The excited states associated with these systems can be classified as transient UEGs, with homogeneous electron density only for specific values of the sphere radius.
Article
Chemistry, Physical
Martial Boggio-Pasqua, Denis Jacquemin, Pierre-Francois Loos
Summary: This study evaluates the accuracy of CASPT3 in molecular excited states and finds that CASPT3 provides similar accuracy to CASPT2 when applying the IPEA shift. However, CASPT3 is almost insensitive to the IPEA shift and shows a slight improvement in accuracy when it is switched off.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Pierre-Francois Loos, Filippo Lipparini, Devin A. Matthews, Aymeric Blondel, Denis Jacquemin
Summary: In this study, the possibilities of the equation-of-motion formalism relying on the approximate fourth-order coupled-cluster (CC) method, CC4, for determining highly accurate vertical excitation energies in small organic compounds are explored. It is demonstrated that CC4 is an excellent approximation to CCSDTQ for excited states with a dominant contribution from single excitations, with an average deviation of 0.003 eV. Additive basis set correction schemes are also assessed and found to be beneficial, with their accuracy depending on the specific scheme. Furthermore, CC4 is used to improve theoretical best estimates of vertical excitation energies in the QUEST database for molecules containing between four and six (nonhydrogen) atoms.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Yann Damour, Pierre-Francois Loos, Rau'l Quintero-Monsebaiz, Michel Caffarel, Denis Jacquemin, Fabris Kossoski, Anthony Scemama
Summary: We computed ground- and excited-state dipole moments and oscillator strengths using the Configuration Interaction using a Perturbative Selection made Iteratively (CIPSI) method, obtaining near-FCI estimates. By calculating 35 ground- and excited-state properties in 11 small molecules, we assessed the accuracy of high-order coupled-cluster (CC) calculations with up to quadruple excitations. Our results show that increasing the excitation degree of the CC expansion reduces the average error with respect to the near-FCI reference values by approximately 1 order of magnitude.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Fabris Kossoski, Pierre-Francois Loos
Summary: We introduce and benchmark a systematically improvable route for excited-state calculations, labeled state-specific configuration interaction (Delta CI), which is a promising alternative to more established methodologies. The Delta CI route can handle challenging multireference problems, singly and doubly excited states, from closed-and open-shell species, with overall comparable accuracy. However, it is reliable only for relatively low-lying excited states in its current form.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Editorial Material
Chemistry, Physical
Martin Head-Gordon, Andrew T. B. Gilbert, Pierre-Francois Loos, Leo Radom
Summary: This article serves as an introduction to a Special Issue dedicated to Peter M. W. Gill, a renowned theoretical chemist, providing a brief scientific biography of his accomplishments.
Article
Chemistry, Physical
Enzo Monino, Pierre-Francois Loos
Summary: In recent years, Green's function methods have gained a lot of attention for their ability to target charged and neutral excitations. The well-established GW approximation accurately predicts ionization potentials and electron affinities, and can be extended to neutral excitations using the BSE formalism. This study investigates the connections between various Green's function methods and evaluates their performance for charged and neutral excitations, with comparisons to other second-order wave function methods. Additionally, the singlet-triplet gap of cycl[3,3,3]azine, a model molecular emitter for thermally activated delayed fluorescence, is calculated to demonstrate the necessity of a second-order BSE kernel with dynamical correction.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Sara Giarrusso, Pierre-Francios Loos
Summary: This study calculates the functionals of the ground state and two excited states of the asymmetric Hubbard dimer, and finds that there is a specific relationship between the energy and functional of each state.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Roland Assaraf, Emmanuel Giner, Vijay Gopal Chilkuri, Pierre-Francois Loos, Anthony Scemama, Michel Caffarel
Summary: In diffusion Monte Carlo, the configuration space is sampled by randomly moving walkers. Previous research on the Hubbard model has shown that the probability for a walker to stay in the same state for a certain amount of time follows a Poisson distribution, and the dynamics of on-state can be integrated out exactly, connecting only different states. In this study, we extend this idea to the general case of a walker trapped within domains of arbitrary shape and size, deriving the equations of the resulting effective stochastic dynamics. The longer the average time the walker spends within the domains, the greater the reduction in statistical fluctuations. A numerical application to the Hubbard model is presented. Although this work is presented for (discrete) finite linear spaces, it can be generalized to continuous configuration spaces without fundamental difficulties.
Article
Chemistry, Physical
Andrew M. Teale, Trygve Helgaker, Andreas Savin, Carlo Adamo, Balint Aradi, Alexei Arbuznikov, Paul W. Ayers, Evert Jan Baerends, Vincenzo Barone, Patrizia Calaminici, Eric Cances, Emily A. Carter, Pratim Kumar Chattaraj, Henry Chermette, Ilaria Ciofini, T. Daniel Crawford, Frank De Proft, John F. Dobson, Claudia Draxl, Thomas Frauenheim, Emmanuel Fromager, Patricio Fuentealba, Laura Gagliardi, Giulia Galli, Jiali Gao, Paul Geerlings, Nikitas Gidopoulos, Peter M. W. Gill, Paola Gori-Giorgi, Andreas Gorling, Tim Gould, Stefan Grimme, Oleg Gritsenko, Hans Jorgen Aagaard Jensen, Erin R. Johnson, Robert O. Jones, Martin Kaupp, Andreas M. Koster, Leeor Kronik, Anna Krylov, Simen Kvaal, Andre Laestadius, Mel Levy, Mathieu Lewin, Shubin Liu, Pierre-Francois Loos, Neepa T. Maitra, Frank Neese, John P. Perdew, Katarzyna Pernal, Pascal Pernot, Piotr Piecuch, Elisa Rebolini, Lucia Reining, Pina Romaniello, Adrienn Ruzsinszky, Dennis R. Salahub, Matthias Scheffler, Peter Schwerdtfeger, Viktor N. Staroverov, Jianwei Sun, Erik Tellgren, David J. Tozer, Samuel B. Trickey, Carsten A. Ullrich, Alberto Vela, Giovanni Vignale, Tomasz A. Wesolowski, Xin Xu, Weitao Yang
Summary: This paper provides an informal review and discussion on the history, present status, and future of density-functional theory (DFT) by 70 workers in the field. The format of a roundtable discussion allowed participants to express their views through 302 individual contributions to a preset list of 26 questions. Supported by a bibliography of 777 entries, the paper offers a comprehensive snapshot of DFT in 2022.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Martial Boggio-Pasqua, Denis Jacquemin, Pierre-Francois Loos
Summary: This study evaluates the accuracy of CASPT3 in molecular excited states based on 280 reference vertical transition energies extracted from the QUEST database. The results show that CASPT3 provides similar accuracy to CASPT2 when applying the IPEA shift, with a slight reduction in mean absolute error when the shift is turned off.
JOURNAL OF CHEMICAL PHYSICS
(2022)
