Article
Physics, Multidisciplinary
Yijian Zou, Karthik Siva, Tomohiro Soejima, Roger S. K. Mong, Michael P. Zaletel
Summary: This study introduces two related non-negative measures of tripartite entanglement and shows that states with nonzero measures have nontrivial entanglement. Additionally, it demonstrates that these entanglement measures in one dimension depend only on the emergent low-energy theory. For a gapped system, it argues that entanglement measures either both nonzero or both zero, depending on the system's ground state. Furthermore, a numerical algorithm is developed for computing entanglement measures in critical systems.
PHYSICAL REVIEW LETTERS
(2021)
Article
Computer Science, Interdisciplinary Applications
Justin A. Reyes, Dan C. Marinescu, Eduardo R. Mucciolo
Summary: This paper explores the exact computation of tensor network contractions on two-dimensional geometries and presents a heuristic improvement to reduce computing time, memory usage, and communication time. The results demonstrate that cloud computing is a viable alternative to supercomputers for scientific applications of this nature.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Libo Liang, Wei Zheng, Ruixiao Yao, Qinpei Zheng, Zhiyuan Yao, Tian-Gang Zhou, Qi Huang, Zhongchi Zhang, Jilai Ye, Xiaoji Zhou, Xuzong Chen, Wenlan Chen, Hui Zhai, Jiazhong Hu
Summary: The article presents a novel method of probing quantum many-body correlation by ramping dynamics. The researchers demonstrate this method experimentally by studying the Bose-Hubbard model with ultracold atoms in three-dimensional optical lattices. This method provides important insights into the physical properties of quantum systems.
Article
Physics, Multidisciplinary
DinhDuy Vu, Ke Huang, Xiao Li, S. Das Sarma
Summary: We investigated many-body localization (MBL) of interacting one-dimensional lattice fermions in random and quasiperiodic models, with a focus on the role of interaction range. Our results revealed a qualitative symmetry between weak and strong interaction limits for short-range interactions, while for long-range interactions, the system was always many-body localized and similar to a pinned Wigner crystal.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Ruoshui Wang, Timothy H. Hsieh, Guifre Vidal
Summary: In this study, we used matrix product techniques to investigate the performance of two algorithms for obtaining the ground state of a quantum many-body Hamiltonian in infinite systems. The first algorithm is a generalization of the quantum approximate optimization algorithm, which uses a quantum computer to evolve an initial product state into an approximation of the ground state by alternating between two Hamiltonians. The second algorithm is the variational imaginary time ansatz, which uses a classical computer to simulate the ground state via alternating imaginary time steps with two Hamiltonians.
Article
Physics, Condensed Matter
Klaus Morawetz
Summary: Quantum anomalies can be avoided by many-body correlations, serving as a shortcut for single-particle field theory to explain many-body effects. By reinterpreting many-body averaging, a new interpretation of quantum fluctuations is established.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Tom Vieijra, Jannes Nys
Summary: Quantum state optimization using the variational principle has recently gained attention due to the development of more expressive wave functions. By embedding global non-Abelian symmetries, the accuracy of Ansatz in representing frustrated two-dimensional J(1)-J(2) model on a square lattice is improved. The methodology guarantees ground state with total spin zero and enables representation of excited states with definite quantum numbers associated to symmetries without modifying network architecture.
Article
Mathematics
Wolfgang Rump
Summary: Auslander proved that the existence of almost split sequences is equivalent to the presence of isolated singularity on a complete regular local ring. This concept has become important in areas such as commutative algebra, non-commutative singularity theory, and Gorenstein homological algebra.
MATHEMATISCHE ZEITSCHRIFT
(2022)
Article
Materials Science, Multidisciplinary
Yogeshwar Prasad, Arti Garg
Summary: In a one-dimensional system of spinless fermions, many-body localization (MBL) is studied in the presence of random interactions decaying as a power-law. The system exhibits a broad nonergodic subdiffusive phase before MBL, and the critical disorder for the ergodic to nonergodic transition increases with the range of interactions. Random power-law interactions induce multifractal eigenfunctions and nonergodic subdiffusive phase in the spectrum of the system.
Article
Materials Science, Multidisciplinary
Ke Huang, DinhDuy Vu, Xiao Li, S. Das Sarma
Summary: We study the many-body localization (MBL) in the quasiperiodic t1 -t2 model, paying attention to the effect of the next-nearest-neighbor (NNN) hopping t2, which leads to a single-particle mobility edge. The calculated phase diagram can be divided into three distinct regions based on the strength of the short-range interaction U. For weak interactions (U << t1), the model is always in a nonthermal state. For intermediate interactions (U - t1), the thermal-MBL phase transition in this model is qualitatively similar to the Aubry-Andre (AA) model, consistent with experimental observations. For strong interactions (U >> t1), the NNN hopping introduces qualitatively new physics by breaking the Hilbert space fragmentation seen in the AA model. The relevance of NNN hopping depends on the strength of the interaction.
Article
Physics, Multidisciplinary
Abhishodh Prakash, J. H. Pixley, Manas Kulkarni
Summary: In this study, we theoretically investigated correlations deep in the spectrum of many-body-localized systems. We derived an exact analytical expression for the spectral form factor of Poisson spectra, which proved to be in good agreement with numerical results from two models exhibiting many-body localization. Additionally, we identified a universal regime that is insensitive to the global density of states and spectral edge effects.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Chemistry, Physical
Mozhdeh Shiranirad, Christian J. Burnham, Niall J. English
Summary: Machine-learned potentials (MLPs) are used to bridge the gap between empirical and quantum-mechanical methods, and face the challenge of predicting many-body energy when determining system characteristics. A finely-trained MLP model successfully predicts the many-body energy of argon clusters with an error within a few meV.
Article
Mathematics, Applied
Peter Benner, Venera Khoromskaia, Boris Khoromskij, Cleophas Kweyu, Matthias Stein
Summary: This paper presents a new regularization scheme for the linearized Poisson-Boltzmann equation, which splits the target potential into short- and long-range components localized in the molecular region, leading to efficient computation and improved accuracy of the solution.
SIAM JOURNAL ON SCIENTIFIC COMPUTING
(2021)
Article
Engineering, Mechanical
Cruz Y. Li, Zengshun Chen, Tim K. T. Tse, Asiri U. Weerasuriya, Xuelin Zhang, Yunfei Fu, Xisheng Lin
Summary: This study focuses on the nuances of dynamic mode decomposition (DMD) sampling and investigates how sampling range and resolution affect the convergence of DMD modes. The results show that the stabilization state is the optimal state for modal convergence, while oversampling leads to algorithmic instability. The convergence of sampling resolution depends on mode-specific dynamics.
NONLINEAR DYNAMICS
(2022)
Article
Materials Science, Multidisciplinary
Angelo Russomanno, Michele Fava, Markus Heyl
Summary: In this study, large-scale exact diagonalization was used to investigate the quantum Ising chain with long-range power-law interactions. The level-spacing statistics indicate a Wigner-Dyson distribution and quantum chaos for all alpha > 0. However, the microcanonical entropy is nonconvex for alpha < 1 due to energetically separated multiplets in the spectrum.
Article
Chemistry, Physical
Caroline T. Sargent, Derek P. Metcalf, Zachary L. Glick, Carlos H. Borca, C. David Sherrill
Summary: Using the many-body expansion method, we predicted crystal lattice energies (CLEs) with flexibility in theoretical methods. We computed two-body contributions of 23 molecular crystals using different quantum chemical levels and compared them with coupled-cluster in the complete basis set (CBS) limit. Accurate calculations were achieved for interaction energies of distant dimers using certain methods, reducing the computational expense of coupled-cluster by up to 98%.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Vinicius Wilian D. Cruzeiro, Yuanheng Wang, Elisa Pieri, Edward G. Hohenstein, Todd J. Martinez
Summary: This article introduces how to set up the GPU-accelerated electronic structure program TeraChem as an electronic structure server, which can be easily accessed by third-party client programs. The client interface, called TeraChem protocol buffers (TCPB), has been designed for ease of use and compatibility with multiple programming languages. By incorporating the TCPB client into Amber for QM/MM simulations, significant time savings and speedup have been achieved compared to prior implementations. The practical application of TCPB is demonstrated through the computation of the free energy profile of a model chromophore.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Review
Chemistry, Physical
Umberto Raucci, Hayley Weir, Sukolsak Sakshuwong, Stefan Seritan, Colton B. Hicks, Fabio Vannucci, Francesco Rea, Todd J. Martinez
Summary: This article outlines methods to eliminate the barriers preventing the wider chemistry community from performing quantum chemistry calculations. These methods include GPU-accelerated quantum chemistry in the cloud, AI-driven natural molecule input methods, and extended reality visualization. The article also highlights the exciting applications of these methods in computing and visualizing spectra, 3D structures, molecular orbitals, and other chemical properties.
ANNUAL REVIEW OF PHYSICAL CHEMISTRY
(2023)
Article
Chemistry, Medicinal
Rameshwar L. Kumawat, C. David Sherrill
Summary: High-order quantum chemistry methods were used to study the intermolecular interaction energies and their components for hydrogen-bonded DNA nucleobase pairs and non-natural Hachimoji nucleobase pairs. The most attractive component of the interaction energies was found to be the electrostatic interactions, followed closely by the sum of induction/polarization and London dispersion. Non-natural Hachimoji base pairs exhibited stronger interactions than the corresponding natural base pairs, while the natural base pairs were more stabilized in their Hoogsteen geometries. Hoogsteen geometries were less favorable for non-natural Hachimoji base pairs compared to Watson-Crick geometries.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Editorial Material
Chemistry, Physical
Michele Ceriotti, Lasse Jensen, David E. Manolopoulos, Todd Martinez, David R. Reichman, Francesco Sciortino, C. David Sherrill, Qiang Shi, Carlos Vega, Lai-Sheng Wang, Emily A. Weiss, Xiaoyang Zhu, Jenny Stein, Tianquan Lian
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Carlos H. Borca, Zachary L. Glick, Derek P. Metcalf, Lori A. Burns, C. David Sherrill
Summary: The use of many-body expansion (MBE) method, combining CCSD(T)/CBS for closest dimers and trimers and MP2 for more distant ones, shows promising results in efficiently calculating lattice energies in organic crystals. The effectiveness of MP2(+ATM) as a replacement for CCSD(T)/CBS is demonstrated. The CCSD(T)/CBS best estimate of the lattice energy at 0 K is -54.01 kJ mol(-1).
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Yi Xie, Zachary L. L. Glick, C. David Sherrill
Summary: This study investigates the three-body dispersion contribution to crystal lattice energies in benzene, carbon dioxide, and triazine. By using various computational methods, it is observed that these contributions converge rapidly with increasing intermolecular distances. The closest-contact distance, R-min, shows a strong correlation with the three-body contribution, while R-max is used as a cutoff criterion for considering the number of trimers. The results suggest that the MP2+ATM method can be used to compute trimers with R-min > 4 angstrom to reduce computational cost.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
David M. G. Williams, Eirik F. Kjonstad, Todd J. Martinez
Summary: It is found that the geometric phase effect is correctly reproduced around defective excited-state conical intersections in coupled cluster theory, indicating that these intersections are local artifacts.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Soren Holm, Pablo A. Unzueta, Keiran Thompson, Todd J. Martinez
Summary: In this study, a graph neural network model is developed and trained to correct the basis set incompleteness error between a small and large basis set at the RHF and B3LYP levels of theory. The results show that fitting an ML model to correct the BSIE is better at generalizing to systems not seen during training compared to fitting to the total potential. Acceptable performance is achieved when the training data sufficiently resemble the systems one wants to make predictions on.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Multidisciplinary Sciences
Y. Liu, D. M. Sanchez, M. R. Ware, E. G. Champenois, J. Yang, J. P. F. Nunes, A. Attar, M. Centurion, J. P. Cryan, R. Forbes, K. Hegazy, M. C. Hoffmann, F. Ji, M. F. Lin, D. Luo, S. K. Saha, X. Shen, X. J. Wang, T. J. Martinez, T. J. A. Wolf
Summary: Combining ultrafast electron diffraction and ab initio dynamics simulations, the authors visualize the structure of a pericyclic minimum, also known as a pericyclic minimum, in real time in a photochemical reaction. Electrocylic reactions involve the simultaneous formation and cleavage of sigma and pi bonds through a cyclic structure. This research provides experimental evidence for the importance of this structure in electrocyclic reactions.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Philip M. Nelson, Zachary L. Glick, C. David Sherrill
Summary: The focal-point approximation combines multiple lower-accuracy, faster computations to estimate a high-accuracy, slow quantum chemistry computation. By combining MP2 with CCSD(T) methods, the focal-point CCSD(T) method can approach the complete basis set (CBS) limit with only triple-xi basis sets. Compared with experimental values, the predicted harmonic and fundamental frequencies using the focal-point method have smaller mean absolute errors, and the computation time required is much less, especially for larger molecules.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Rui Xu, Jan Meisner, Alexander M. Chang, Keiran C. Thompson, Todd J. Martinez
Summary: Our recent success in utilizing GPUs to speed up quantum chemistry computations has led to the creation of the ab initio nanoreactor, a computational framework for automatic reaction discovery and kinetic model construction. In this work, we apply the ab initio nanoreactor to study methane pyrolysis, uncovering the elementary reactions through GPU-accelerated simulations and refining the reaction paths using transition state theory. With 53 species and 134 reactions, the kinetic model derived from the discovered reactions is validated against experimental data and literature models. We also demonstrate the effectiveness of local brute force and Monte Carlo sensitivity analysis for identifying important reactions and improving the accuracy of the kinetic model.
Article
Physics, Nuclear
N. Schunck, M. Verriere, G. Potel Aguilar, R. C. Malone, J. A. Silano, A. P. D. Ramirez, A. P. Tonchev
Summary: Fission data are crucial for nucleosynthesis simulations and nuclear forensics. The characteristics of fission for odd-mass nuclei, as well as even-even nuclei, are important in various applications. Fission theories that aim at describing fission dynamics are usually based on nuclear mean-field theories. In this article, we use the blocking prescription of the Hartree-Fock-Bogoliubov theory with Skyrme energy functionals to investigate odd-mass uranium isotopes. Our results show that the fission fragment distributions depend significantly on the spin of the odd neutron. We propose a methodology based on the calculation of the spin distribution to predict the charge and mass distributions in odd-mass nuclei.
Article
Chemistry, Physical
Alexander M. Chang, Jan Meisner, Rui Xu, Todd J. Martinez
Summary: This study examines the effectiveness of using metadynamics, attractive potentials, and local thermostats for accelerating reaction discovery. By constructing different reaction networks, it is found that a combination of accelerating forces is best suited for reaction discovery.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
