Article
Chemistry, Physical
James Damewood, Daniel Schwalbe-Koda, Rafael Gomez-Bombarelli
Summary: Efficient and accurate calculation of thermodynamic potentials and observables is crucial for the application of statistical mechanics simulations in materials science. Existing naive Monte Carlo methods cannot handle the calculation demands of complex materials, so we transform machine learning-based generative models into the semi-grand canonical ensemble to address this issue. The resulting models are transferable across different thermodynamic conditions and can be used with various internal energy models.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Quantum Science & Technology
Hong-Mei Li, Guo-Mo Zeng
Summary: The quantum walks of a three-boson system on a one-dimensional lattice were investigated using the Bose-Hubbard model with two- and three-body interactions. The study focused on the formation of particle pairs and trios for different initial states, as well as the variations of correlations and density distribution with interaction strength.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Electrochemistry
Mohammad J. Eslamibidgoli, Jun Huang, Piotr M. Kowalski, Michael H. Eikerling, Axel Gross
Summary: Nickel-based oxides are highly active and cost-effective materials for the oxygen evolution reaction in alkaline conditions. Recent experimental studies have shown the importance of surface deprotonation and alkali metal cation adsorption for the activity. The study emphasizes the importance of double-layer effects for the most stable interface structure.
ELECTROCHIMICA ACTA
(2021)
Article
Optics
M. Gaudesius, Y-C Zhang, T. Pohl, R. Kaiser, G. Labeyrie
Summary: This study analyzed the spatiotemporal instabilities of large clouds of cold atoms in a magneto-optical trap through three-dimensional simulations. The research revealed different dynamical regimes in the phase space of the instabilities, providing a detailed analysis of the experimental observations.
Article
Chemistry, Physical
Shibin Wang, Weiwei Xu, Ge Feng, Wenwen Li, Jianguo Wang
Summary: The surface state of electrodes in electrochemical reactions is significantly affected by applied external potential and the exposed solvent condition. This study used grand canonical density functional theory (DFT) calculations to systematically investigate the surface state and oxygen evolution reaction (OER) performances of the Ru (0 0 0 1) surface. Equilibrium Pourbaix diagrams demonstrated the oxidation state of either O* or OH*. Even in the negative polarized potential of USHE < 0.0 V, the Ru (0 0 0 1) surface exhibited the surface state of 1/9 ML O* preoccupying instead of the clean surface. Mechanistic studies revealed that in acidic OER process on clean Ru (0 0 0 1) surface, the oxygen coupling mechanism is more favorable than the nucleophilic attack mechanism involving OOH* intermediate formation.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2023)
Article
Physics, Multidisciplinary
P. Senger
Summary: The fundamental properties of dense nuclear matter in massive stellar objects are largely unknown, and research focuses on high-density EOS and microscopic degrees of freedom of strongly interacting matter. Experimental data on these topics are scarce, and future laboratory experiments at heavy-ion research centers are planned to explore this terra incognita, complementing astronomical observations and shedding light on QCD matter at neutron star core densities.
Article
Chemistry, Physical
Mashooq A. Wani, Shubhangi A. Athawale, R. M. Belekar
Summary: The present study successfully synthesized two new centrosymmetric pyrophosphates Li2MgP2O7:Eu3+ and ZnMgP2O7:Eu3+ compounds by the wet-chemical method. The structures and phase purities of these compounds were confirmed by XRD analysis and FT-IR. These compounds exhibit strong optical absorption over a wavelength range of 200-800 nm, and their photoluminescence emission spectra reveal their structural characteristics and potential commercial applications.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Physics, Multidisciplinary
Nilanjan Kundu, Ajay Nath, Jayanta Bera, Suranjana Ghosh, Utpal Roy
Summary: We provide a generic and precise analytical model for achieving negative absolute temperature in ultracold atoms under a quasi-periodic optical lattice and an expulsive trap. By controlling the trap parameters, we explore all the necessary conditions for achieving negative temperature domain and perform a quantitative estimation of the temperature in the negative domain. Numerical stability analysis confirms the stability of the proposed family of solutions and connects it to the merit of negative temperature through mean deviation data with varied trap parameters.
Article
Optics
Sergey A. Saakyan, Vladimir A. Sautenkov, Stepan V. Klimov, Alexander A. Nazarov, Andrey A. Bobrov, Boris B. Zelener
Summary: We investigate the dynamics of time-resolved Rydberg excitation for Lithium atoms in a magneto-optical trap. The loss of neutral atoms due to Rydberg excitation is detected by analyzing the absorption of a weak probe beam. Our experiment verifies the existence of both density-dependent excitation blockade and excitation facilitation effects. Furthermore, we measure the frequency shift of the Rydberg transition at different durations of excitation pulses, which can be attributed to the formation of ultracold ions from the high-density ensemble of Rydberg atoms.
JOURNAL OF RUSSIAN LASER RESEARCH
(2023)