Article
Materials Science, Multidisciplinary
Yanan Sun, Jian-Ping Lv
Summary: The recent discovery of extraordinary-log universality has sparked intense interest in classical and quantum boundary critical phenomena. Through quantum Monte Carlo simulations, this study investigates the quantum edge criticality of a two-dimensional Bose-Hubbard model, revealing the transition of the edges from an insulating bulk to a superfluid phase. The open edges exhibit special, ordinary, and extraordinary critical phases at the bulk critical point.
Article
Multidisciplinary Sciences
Vijin Venu, Peihang Xu, Mikhail Mamaev, Frank Corapi, Thomas Bilitewski, Jose P. D'Incao, Cora J. Fujiwara, Ana Maria Rey, Joseph H. Thywissen
Summary: Exchange-antisymmetric pair wavefunctions in fermionic systems can lead to unconventional superconductors and superfluids. Creating and controlling these states in quantum systems, such as ultracold gases, can enable new types of quantum simulations, topological quantum gates, and exotic few-body states. This study demonstrates the creation of isolated pairs of strongly interacting fermionic atoms in a multiorbital three-dimensional optical lattice, where the p-wave interaction energies can be accurately measured and tuned. The absence of three-body processes allows the observation of elastic unitary p-wave interactions and coherent oscillations between free-atom and interacting-pair states.
Article
Chemistry, Physical
Bing Huang, O. Anatole von Lilienfeld, Jaron T. Krogel, Anouar Benali
Summary: Quantum diffusion Monte Carlo (DMC) has shown great potential in predicting the energetics and properties of molecules and solids through solving the electronic many-body Schrödinger equation. When coupled with quantum machine learning (QML), DMC can alleviate computational burden, making it a promising method for large systems. Three crucial approximations, including fixed-node approximation, universal reference for chemical bond dissociation energies, and scalable minimal amons-set-based QML (AQML) models, are discussed. Numerical evidence suggests that even modestly sized QMC training data sets can accurately predict total energies throughout chemical space.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Peter D. Reyntjens, Sabyasachi Tiwari, Maarten L. van de Put, Bart Soree, William G. Vandenberghe
Summary: By studying the magnetic properties of PtSe2 intercalated with Ti, V, Cr, and Mn, different magnetic groundstates and critical temperatures were identified. The introduction of Pt vacancies was shown to alter the magnetic groundstate and critical temperature of intercalated PtSe2, suggesting the potential for controlling the magnetic properties through defect engineering.
Article
Materials Science, Multidisciplinary
Alex Taekyung Lee, Hyowon Park, Anh T. Ngo
Summary: This study investigates the impact of the off-diagonal elements of the Wannier Hamiltonian on the electronic structure of Li2MnO3 using dynamical mean field theory calculations. The presence of these elements significantly reduces the energy gap, even when using local coordinates. By diagonalizing the Mn d block and applying a rotation matrix, the energy gap can be enhanced. Additionally, considering the small double counting energy is crucial for reducing p-d hybridization to achieve the experimental energy gap. This study also suggests the effectiveness of using the density functional theory plus dynamical mean field theory method to investigate low-symmetry materials.
Article
Chemistry, Physical
Oliver A. Bramley, Timothy J. H. Hele, Dmitrii Shalashilin
Summary: Zombie states are a formalism that describes coupled coherent fermionic states in a computationally tractable manner. This study extends the previous work on Zombie states and develops efficient algorithms for evaluating operators and addressing normalization. It also presents techniques for improving accuracy and calculating low-lying excited states.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Jan Kessler, Francesco Calcavecchia, Thomas D. Kuehne
Summary: Inspired by the universal approximation theorem and the widespread adoption of artificial neural network techniques, feed-forward neural networks are proposed as a general purpose trial wave function for quantum Monte Carlo simulations of continuous many-body systems. The accuracy of the trial wave functions was demonstrated by studying an exactly solvable model system of two trapped interacting particles and the hydrogen dimer. The whole many-body wave function can be represented by a neural network for simple model systems, while the antisymmetry condition of non-trivial fermionic systems is incorporated by means of a Slater determinant.
ADVANCED THEORY AND SIMULATIONS
(2021)
Article
Multidisciplinary Sciences
Victor Helson, Timo Zwettler, Farokh Mivehvar, Elvia Colella, Kevin Roux, Hideki Konishi, Helmut Ritsch, Jean-Philippe Brantut
Summary: A density wave (DW) is a type of long-range order in quantum matter that is associated with self-organization into a crystalline structure. The interplay of DW order with superfluidity presents a significant theoretical challenge. In this study, a tunable quantum Fermi gas with both strong, contact interactions and photon-mediated, spatially structured long-range interactions in an optical cavity is realized. The DW order is stabilized in the system above a critical long-range interaction strength, which is identified through superradiant light-scattering properties. The experimental setup provides a fully tunable and microscopically controllable platform for studying the interplay of superfluidity and DW order.
Article
Chemistry, Physical
Anthony Scemama, Andreas Savin
Summary: This article calculates the probabilities of finding a chosen number of electrons in flexible domains of space using highly correlated wave functions. Quantum mechanics can increase the probabilities of chemically relevant electron arrangements in these regions. However, the probability of having a specific arrangement, such as chemical formulas (bonds or atoms), is often low despite being maximal. It is useful to consider alternative distributions of electrons and to include exchanges of electrons between different types of regions.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Julia A. Davies, Christoph Schran, Fabien Brieuc, Dominik Marx, Andrew M. Ellis
Summary: In this study, infrared spectroscopy is used to investigate 4HeN center dot center dot center dot H3O+ complexes. It is found that the rotational behavior of H3O+ undergoes significant changes as 4He atoms are added.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Inorganic & Nuclear
Mousumi Dutta, Shubham Bisht, Prabir Ghosh, Alexandra Ioana Chilug, Dallas Mann, Cristian Enachescu, Michael Shatruk, Pradip Chakraborty
Summary: Structural studies have been conducted on dehydrated coordination networks to investigate the high-symmetry cubic structure and spin-crossover behavior of the [NixCo1-x(bpy)(3)][LiCr(ox)(3)] series.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Jonas Feldt, Antoine Bienvenu, Roland Assaraf
Summary: In this paper, a new estimator in the variational Monte Carlo framework is proposed, which utilizes numerically cheap single-core subsamplings to improve the estimation of molecular properties. Furthermore, a spin-dependent core definition is introduced to simplify the algorithm and enhance its efficiency.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Giovani L. Rech, Andre L. Martinotto, Janete E. Zorzi, Claudio A. Perottoni
Summary: The relative stability between the crystal structure of alpha-F-2, space group C2/c, and a hypothesized high-pressure phase, space group Cmce, was investigated using Density Functional Theory and Quantum Monte Carlo calculations. The analysis of the phonon dispersion spectra showed that the Cmce phase exhibits dynamical instability near the Gamma-point at ambient pressure, which disappears under increasing pressure. This instability is attributed to the absence of sigma-holes in the fluorine molecule, resulting in repulsive head-to-head interactions between molecules.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Yuichi Motoyama, Kazuyoshi Yoshimi, Junya Otsuki
Summary: Analytic continuation from the imaginary-time Green's function to the spectral function is crucial for studying the dynamical properties of quantum many-body systems. However, this process is unstable and has advantages and disadvantages. Combining SpM AC with Pade approximation in the SpM-Pade method can provide more accurate and stable results.
Article
Materials Science, Multidisciplinary
Titas Chanda, Jakub Zakrzewski
Summary: In this study, many-body localization (MBL) features are explored in a large spin chain model with long-range interactions. The model represents cold atoms inside a cavity driven by an external laser field, where long-range interactions originate from rescattering of cavity photons. Previous studies were limited to small system sizes that could be exactly diagonalized. By utilizing tensor network algorithms, nonergodic features and MBL are demonstrated to exist in this model for random disorder and in the presence of a tilted potential, even for system sizes relevant to experiments.
Article
Chemistry, Physical
Milagros F. Morcillo, Jose M. Alcaraz-Pelegrina, Antonio Sarsa
Article
Chemistry, Physical
Alvaro Luzon, Enrique Buendia, Francisco J. Galvez
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2020)
Article
Spectroscopy
Antonio Ortiz-Mora, Antonio Diaz-Soriano, Antonio Sarsa, Milan S. Dimitrijevic, Cristina Yubero
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2020)
Article
Multidisciplinary Sciences
Wentao Zhang, Pablo Maldonado, Zuanming Jin, Tom S. Seifert, Jacek Arabski, Guy Schmerber, Eric Beaurepaire, Mischa Bonn, Tobias Kampfrath, Peter M. Oppeneer, Dmitry Turchinovich
NATURE COMMUNICATIONS
(2020)
Article
Optics
D. Martinez-Munoz, A. Ortiz-Mora, A. Dengra, A. Sarsa-Rubio, A. Diaz-Soriano
Summary: This paper proposes a new Sierpinski fractal pattern implementation as a tool to fine-tune the properties of Microstructured Optical Fibers (MOFs). It has been applied to an existing hexagonal-MOF photonic crystal fiber (PCF) with solid core to decrease its chromatic dispersion, nonlinear and loss properties, demonstrating the flexibility of these fiber designing techniques. Additionally, a study modeling possible fluctuations in properties design due to geometrical perturbations during the manufacturing process is included.
Article
Spectroscopy
J. M. Alcaraz-Pelegrina, A. Sarsa, M. S. Dimitrijevic, C. Yubero
Summary: In this paper, laboratory plasmas were characterized using Optical Emission Spectroscopy techniques, with a focus on the Stark effect on the Hydrogen emitter atom and the impact of ion collisions. The analysis was extended to cover a wide range of plasma conditions, highlighting the importance of understanding the internal processes of the Hydrogen emitter atom.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2022)
Article
Physics, Multidisciplinary
Milagros F. Morcillo-Arencibia, Antonio J. Sarsa, Jose Manuel Alcaraz-Pelegrina
Summary: The study discusses the stability of confined atoms when released from confinement, focusing on the effects of different confining cage sizes on the energy and electronic structure. The oscillations observed in the atomic properties as a function of cage size can be explained by the shell structure of the atom.
Article
Physics, Multidisciplinary
Milagros F. Morcillo-Arencibia, Jose Manuel Alcaraz-Pelegrina, Antonio J. Sarsa, Juan M. Randazzo
Summary: The ground state energy of a helium atom in a spherical multilayer quantum dot was calculated. The energy depended on the impurity location inside the quantum dot. A core/shell/well/shell structure with a parabolic confinement was used to model the multilayer quantum dot. The Configuration Interaction method and Diffusion Monte Carlo were employed to solve the Schrodinger equation. The results showed that the lowest energy configuration varied with the size of the different layers, and the agreement between Configuration Interaction and Diffusion Monte Carlo results suggested the suitability of the Configuration Interaction approach for computing excited states.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Chemistry, Physical
Milagros F. Morcillo-Arencibia, Jose Manuel Alcaraz-Pelegrina, Antonio J. Sarsa, Juan M. Randazzo
Summary: In this study, the stability of a hydrogen molecule confined inside a C-60 structure is investigated through an analysis of the electronic spectrum. The study finds that the position of the atoms inside the cavity affects the inter-atomic distance and the energetic configuration of the molecule.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ulrike Ritzmann, Pavel Balaz, Pablo Maldonado, Karel Carva, Peter M. Oppeneer
Article
Materials Science, Multidisciplinary
Pavel Balaz, Karel Carva, Ulrike Ritzmann, Pablo Maldonado, Peter M. Oppeneer
Article
Materials Science, Multidisciplinary
P. Maldonado, T. Chase, A. H. Reid, X. Shen, R. K. Li, K. Carva, T. Payer, M. Horn von Hoegen, K. Sokolowski-Tinten, X. J. Wang, P. M. Oppeneer, H. A. Durr
Article
Nanoscience & Nanotechnology
Jacob Katriel, H. E. Montgomery, A. Sarsa, E. Buendia, F. J. Galvez, K. D. Sen
NANOSYSTEMS-PHYSICS CHEMISTRY MATHEMATICS
(2019)
