Article
Engineering, Environmental
Yanei Xue, Penghui Shao, Mingli Lin, Yixing Yuan, Wenxin Shi, Fuyi Cui
Summary: This study investigates the influence of defects on catalytic activity by optimizing the concentration of sulfur vacancies in a catalyst. The results show that the influence of sulfur vacancy concentration on catalytic activity varies, revealing the fundamental essence of defect behavior affecting crystal catalytic activity.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Chemistry, Physical
Charles Babin, Rainer Stoehr, Naoya Morioka, Tobias Linkewitz, Timo Steidl, Raphael Woernle, Di Liu, Erik Hesselmeier, Vadim Vorobyov, Andrej Denisenko, Mario Hentschel, Christian Gobert, Patrick Berwian, Georgy Astakhov, Wolfgang Knolle, Sridhar Majety, Pranta Saha, Marina Radulaski, Nguyen Tien Son, Jawad Ul-Hassan, Florian Kaiser, Joerg Wrachtrup
Summary: Optically addressable spin defects in silicon carbide (SiC) are a promising platform for quantum information processing, enabling high-fidelity spin qubit operations. However, degradation of spin-optical coherence after integration in nanophotonic structures poses a challenge for scalability towards large-scale quantum networks.
Article
Multidisciplinary Sciences
Dmitriy S. Shapiro
Summary: Under nonequilibrium conditions, quantum optical systems exhibit distinct properties due to the arbitrary occupation numbers of photonic eigenstates, unlike in condensed matter systems limited by the Pauli principle. The study of pseudothermal photon transport between waveguides connected through a cavity reveals a continuous transition between Lorentzian and Gaussian chaotic light emission, characterized by the zero-frequency noise and power-law noise-current relation. The nonperturbative solution for photon dephasing provides insights for experiments involving photon blockade in superconducting qubits, thermal states transfer, and photon statistics probing.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Physical
Lu Gem Gao, Donald G. Fleming, Donald G. Truhlar, Xuefei Xu
Summary: The study reveals that considering reaction-coordinate-dependent vibrational anharmonicity is crucial in calculating tunneling probabilities and kinetic isotope effects. In the reaction of propane with Mu, this decreases the height and width of the vibrationally adiabatic potential barrier, leading to increased rate constants, which is in good agreement with experimental observations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Physics, Multidisciplinary
Adonai R. da Cruz, Michael E. Flatte
Summary: Theoretical calculations predict the anisotropic dissipationless circulating current induced by a spin defect in a two-dimensional electron gas. The shape and spatial extent of these dissipationless circulating currents depend dramatically on the relative strengths of spin-orbit fields with differing spatial symmetry, offering the potential to use an electric gate to manipulate nanoscale magnetic fields and couple magnetic defects. The spatial structure of the magnetic field produced by this current is calculated and provides a direct way to measure the spin-orbit fields of the host, as well as the defect spin orientation, e.g., through scanning nanoscale magnetometry.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Victor Barsan
Summary: The paper introduces a toy model for studying phase transition in an anharmonic solid by utilizing a 2D or 3D lattice structure with quantum quartic oscillators interaction. By replacing the anharmonic quartic potential with a more workable rectangular two well potential, an analytical critical equation is obtained. Applications in nanophysics are briefly mentioned.
ROMANIAN REPORTS IN PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Alfred P. Chernyshev
Summary: A theoretical model has been developed to describe the formation of oxygen vacancies in ceria at the nanoscale. The study found that the characteristic size and morphology of nanoobjects significantly affect the concentration of oxygen vacancies, with size effects occurring below 20 nm and morphology effects increasing with decreasing characteristic size. Additionally, the effects of morphology and size decrease with increasing temperature.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Physics, Multidisciplinary
H. Wilming
Summary: Nondecreasing entropy serves as a necessary and sufficient condition for transforming the state of a physical system by a reversible transformation. This applies to both finite-dimensional quantum mechanics and systems described by probability distributions. The results provide a complete single-shot characterization of von Neumann entropy and Shannon entropy without external randomness.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Sahel Ashhab, Fumiki Yoshihara, Tomoko Fuse, Naoki Yamamoto, Adrian Lupascu, Kouichi Semba
Summary: This study examines the implementation of two-qubit gates in the presence of additional quantum states in the accessible energy range. The results show that the coupling between higher energy levels can increase the gate speed, while weak anharmonicity constrains the system's control speed. By modifying the pulse optimization algorithm, the impact of higher levels can be minimized. Furthermore, the optimal-control gate speeds are compared with those obtained using other protocols.
Article
Materials Science, Multidisciplinary
Huihui Ji, Zhi Yan, Guowei Zhou, Penghua Kang, Zhilan Li, Xiaohong Xu
Summary: This study demonstrates the achievement of electric field-controlled perpendicular magnetic anisotropy (PMA) with excellent performance in strongly correlated oxides. By synthesizing high-quality bilayer heterostructures, the researchers successfully create a bilayer structure with out-of-plane magnetic anisotropy, which is different from the in-plane magnetic easy axis in a single film. The electric field-reversible tunable high-temperature PMA is achieved by manipulating the phase transition in the top layer, enabling the development of oxide-based electronic components.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Astronomy & Astrophysics
V. A. Babenko, N. M. Petrov
Summary: This paper investigates the problem of infinite series divergence in the quantum quartic anharmonic oscillator and proposes an average Pade approximant method to solve it. The method is able to obtain approximations with correct asymptotic behavior as the coupling constant increases. The study demonstrates that the method has significant theoretical and computational advantages in applications, and calculates and analyzes the ground state energy of the anharmonic oscillator extensively.
MODERN PHYSICS LETTERS A
(2022)
Article
Chemistry, Physical
Jan Valenta, Michael Greben, Goutam Pramanik, Klaudia Kvakova, Petr Cigler
Summary: The optical properties of gold nanoclusters emitting near-infrared light were thoroughly investigated at different temperatures and excitation powers. The results showed unique absorption and luminescence characteristics, with potential applications in nanothermometry.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Xiao Su, Rong-Guang Guo, Shuo Xu, Shi-Jie Wang, Xiao-Hong Li, Hong-Ling Cui
Summary: First-principles calculations were utilized to investigate the structural, electronic properties, and quantum capacitance of Ti2CO2 monolayer with different oxygen vacancy concentration. The introduction of oxygen vacancies was found to improve the electronic properties of the system, especially for Ti2CO2 with 5.56% OVC.
Article
Multidisciplinary Sciences
Qi Zhang, Yuhang Guo, Wentao Ji, Mengqi Wang, Jun Yin, Fei Kong, Yiheng Lin, Chunming Yin, Fazhan Shi, Ya Wang, Jiangfeng Du
Summary: The nitrogen-vacancy (NV) center in diamond is crucial for achieving high-fidelity single-shot readout of qubits, with a new spin-to-charge conversion method introduced to suppress spin-flip errors. This technique shows potential for exceeding fault-tolerant thresholds and may have applications in integrated optoelectronic devices.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Marios Zacharias, George Volonakis, Feliciano Giustino, Jacky Even
Summary: In this paper, we present an approach for the treatment of anharmonicity in solids based on the self-consistent phonon theory and the special displacement method. Our method allows for efficient calculation of temperature-dependent anharmonic phonon dispersions with minimal steps for minimizing the system's free energy. The results demonstrate good agreement with experiments and previous studies, and show promise for investigating strongly anharmonic systems.
Article
Engineering, Multidisciplinary
Andres F. Galvis, Pedro A. Santos-Florez, Paulo Sollero, Maurice de Koning, Luiz C. Wrobel
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2020)
Article
Chemistry, Physical
Pedro Antonio Santos-Florez, Carlos J. Ruestes, Maurice de Koning
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Chemistry, Physical
Pedro Antonio Santos-Florez, Maurice de Koning
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Maurice de Koning
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Ingrid de Almeida Ribeiro, Maurice de Koning
Summary: Using nonequilibrium molecular dynamics simulations, this study investigates grain-boundary sliding in ice I-h, finding that a liquid-like layer at the grain boundary significantly facilitates sliding. The study also shows that the presence of the liquid-like layer reduces both the yield stress and the steady-state stress required to maintain sliding.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Ingrid de Almeida Ribeiro, Roberto Gomes de Aguiar Veiga, Maurice de Koning
Summary: The presence of sodium chloride significantly affects the properties of ice crystal grain boundaries by altering water molecule structure, increasing water molecule mobility, and reducing molecular and ionic diffusivities. Additionally, sodium chloride facilitates the grain boundary sliding process.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Ingrid de Almeida Ribeiro, Maurice de Koning, Valeria Molinero
Summary: The anomalous increase in compressibility and heat capacity of supercooled water is attributed to a structural transformation into a four-coordinated liquid. Experimental studies show that kappa(T) and C-p reach their peaks at approximately 229 K. Recently, a pulsed heating procedure (PHP) revealed a significant increase in tetrahedrality around T-W(PHP) = 210 +/- 3 K. However, this discrepancy raises questions about whether the structure and thermodynamics of water are decoupled, or if the shift in T-W is an artifact of PHP.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Jessica Santos Rego, Caetano Rodrigues Miranda, Maurice de Koning
Summary: Using density-functional-theory calculations, the effects of Ca2+ -> Mg2+ substitutions on the mineral structure of tobermorite were analyzed. It was found that Mg substitution leads to a decrease in lattice parameters, an increase in unit cell distortion, enhanced crystal cohesion and reactivity, and overall stiffening of the elastic moduli. However, Mg doping may also result in increased elastic anisotropy.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Multidisciplinary Sciences
Filipe Matusalem, Jessica Santos Rego, Maurice de Koning
Summary: There has been a growing interest in the mechanical properties of superionic (SI) phases of water ice, which play a potential role in the geophysical properties of Neptune and Uranus. This study assessed the mechanical response of high-pressure/temperature solid phases of water using density functional theory calculations and machine learning techniques. The results indicate that SI ices are highly ductile and the plastic flow of the internal icy layers in Neptune and Uranus may be significantly faster than previously foreseen.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Physics, Multidisciplinary
Maurice de Koning, Wei Cai, Claudio Cazorla, Jordi Boronat
Summary: The mass transport properties along dislocation cores in hcp 4He are studied using a fully correlated quantum simulation approach and the PIGS method. The results show that the defective 4He systems have a negligible Bose-Einstein condensate fraction, indicating the absence of intrinsic superfluidity in dislocation cores. This challenges the interpretation of the mass-flux-experiment observations and calls for further experimental investigation.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Maurice de Koning, Wei Cai
Summary: Quantum behavior at mesoscopic length scales is of great interest and has implications for both fundamental physics and technological advancements. This study demonstrates that an effective-Hamiltonian approach used to describe quantum behavior in qubit/oscillator systems can also be applied to understand the intrinsic behavior of quantum materials. By mapping atomistic quantum simulations onto one-dimensional effective Hamiltonians, the study provides quantitative insights into experimental observations in solid He-4.
NPJ QUANTUM MATERIALS
(2022)
Article
Chemistry, Physical
Vitor Fidalgo Candido, Filipe Matusalem, Maurice de Koning
Summary: Superionic water ices, where the oxygen ions occupy a crystal lattice while the protons flow in a liquid-like manner, have gained increasing attention due to their potential role in the magnetic anomalies of ice giants. In this paper, the free energies of these phases are calculated using a hybrid reference system, and the melting temperature is determined for the face-centered cubic (fcc) and liquid phases. The results show that the entropy difference between the two phases is relatively small, primarily due to the large amplitude of vibration of the oxygen ions in the fcc phase at the melting temperature.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Sebastian Ujevic, Vinicius Zampronio, Bruno R. de Abreu, Silvio A. Vitiello
Summary: We investigate strongly correlated many-body systems of bosons and fermions using the path-integral ground state method (PIGS), incorporating the fixed-node approximation (FN-PIGS) to deal with Fermi-Dirac statistics. We discuss in detail the pair density matrices used to construct the full density operator in coordinate representation. We explore the proof-of-concept harmonic oscillator and the helium atom as a representative quantum many-body system, with pure 4He systems demonstrating the method's key features and pure 3He systems benefiting from the fixed-node approximation to resolve the sign problem.
SCIPOST PHYSICS CORE
(2023)
Article
Optics
Renato Pessoa, S. A. Vitiello, L. A. Pena Ardila
Summary: The properties of polarons in an ultracold Fermi gas were studied using Quantum Monte Carlo techniques and both zero-range and square-well potential models. The polaron effective mass, binding energy, and effective coupling were computed, with the latter obtained using Landau-Pomeranchuk's weakly interacting quasiparticle model. The contact parameter was estimated by fitting the pair distribution function of atoms in different spin states.
Article
Physics, Condensed Matter
V. Z. Pedroso, V Zampronio, S. A. Vitiello
Summary: The study investigates the metastable phase of solid He-4 and the role of point defects in its destabilization, showing that the formation energy for vacancies and self-interstitials becomes zero at a pressure of 20 atm, in agreement with experimental observations. Other important properties of He-4 systems are also estimated and compared with existing literature.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
