Article
Multidisciplinary Sciences
Alexandra J. Feinberg, Deepak Verma, Sean M. O. O'Connell-Lopez, Swetha Erukala, Rico Mayro P. Tanyag, Weiwu Pang, Catherine A. Saladrigas, Benjamin W. Toulson, Mario Borgwardt, Niranjan Shivaram, Ming-Fu Lin, Andre Al Haddad, Wolfgang Jager, Christoph Bostedt, Peter Walter, Oliver Gessner, Andrey F. Vilesov
Summary: Through ultrafast x-ray diffraction experiments on xenon-doped He-3 and He-4 nanodroplets, it has been demonstrated that rotational excitation leads to anisotropic and inhomogeneous interactions between the host matrix and enclosed dopants. Superfluid He-4 droplets trap embedded particles with quantum vortices, forming filament-shaped clusters, while dopants in He-3 droplets gather in diffuse, ring-shaped structures along the equator. The shapes of droplets carrying filaments or rings provide direct evidence that rotational excitation causes inhomogeneous dopant distributions.
Article
Physics, Fluids & Plasmas
V. V. Sargsyan, A. A. Hovhannisyan, G. G. Adamian, N. Antonenko, D. Lacroix
Summary: The study examines the time evolution of occupation numbers for fermionic or bosonic oscillators fully coupled to multiple fermionic and bosonic heat baths. The impact of thermal reservoir characteristics on nonstationary population probability is analyzed, with discussions on utilizing the absence of equilibrium for dynamic memory storage in such systems.
Article
Astronomy & Astrophysics
Tiziano Peraro, Lorenzo Tancredi
Summary: The paper elaborates on a method for decomposing multiloop multileg scattering amplitudes into Lorentz-invariant form factors, applicable to both fermionic and bosonic amplitudes. This approach identifies a minimal number of physically relevant form factors and can relate them one to one to independent helicity amplitudes. The method is explicitly discussed in the context of various four- and five-point scattering amplitudes relevant for LHC physics.
Article
Physics, Fluids & Plasmas
Nikhil Gupt, Srijan Bhattacharyya, Arnab Ghosh
Summary: This study presents a unified framework for generalizing the finite-time thermodynamic behavior of bosonic and fermionic Stirling cycles, treating working fluids obeying different statistics equally. By modeling particles as noninteracting oscillators, the study provides interesting generalizations for heat and work definitions, applicable to classical and nonclassical fluids. Results on heat transfer rates at low and high temperatures are derived, showcasing the thermodynamic equivalence between two types of Stirling cycles in the low-temperature quantum regime.
Article
Chemistry, Physical
Andres Montoya-Castillo, Thomas E. Markland
Summary: This paper investigates the dynamics of many-body fermionic systems and derives conditions under which fermionic operators can be replaced by bosonic operators while still capturing the correct dynamics of n-body operators. The analysis provides a guide on how to calculate single- and multi-time correlation functions essential in describing transport and spectroscopy using these simple maps. The applicability of Cartesian maps in capturing correct fermionic dynamics in select models of nanoscopic transport is rigorously analyzed and illustrated with exact simulations of the resonant level model.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Quantum Science & Technology
Stephane Dartois, Ion Nechita, Adrian Tanasa
Summary: We introduce and study the density matrix ensembles of bosonic and fermionic systems, focusing on their entanglement properties. It is shown that random bipartite fermionic density matrices generally exhibit entanglement due to non-positive partial transposition. In the bosonic case, the analysis is more intricate due to the presence of a large positive outlier eigenvalue. The asymptotic ratio between the size of the environment and the system Hilbert space for which random bipartite bosonic density matrices fail the PPT criterion, indicating their entanglement, is computed. Moment computations for tensor-symmetric random matrices are also related to evaluations of circuit counting and interlace graph polynomials for directed graphs.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Optics
L. Ferialdi, L. Diosi
Summary: Wick's theorem provides a connection between time ordered products of bosonic or fermionic fields, and their normal ordered counterparts. The general Wick's theorem is established for both bosonic and fermionic operators, with the surprising result that it is independent of the type of operator involved. By using a few examples, it is shown how the GWT can help reduce the amount of calculations required to solve demanding problems.
Article
Chemistry, Physical
Yaling Ke, Raffaele Borrelli, Michael Thoss
Summary: This article extends the hierarchical equations of motion approach combined with the matrix product state representation to nonequilibrium scenarios of open quantum systems coupled with a hybrid fermionic and bosonic environment. By reformulating the hierarchical equations of motion and applying tensor decomposition, accurate simulations of non-equilibrium quantum dynamics in larger and more complex systems are achieved.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Zae Young Kim, Jeong-Hyuck Park
Summary: Modern technology has introduced new forms of wealth, including digital currency that exists solely in electronic form. The potential impact of its ongoing growth on wealth distribution remains uncertain. This study proposes categorizing contemporary wealth into 'distinguishable' and 'identical' classes, with traditional tangible money falling into the former and financial assets, cryptocurrencies, and non-fungible tokens into the latter. The ownership-based distributions of these classes follow either the Poisson or the geometric distribution, highlighting their distinct features through measures like Gini coefficients. Additionally, aggregating different types of wealth involves a weighted convolution influenced by the number of banks, while Bitcoin adheres to the Bose-Einstein distribution. This novel approach sheds light on the deepening inequality in the modern economy, attributing it to the statistical physics property of wealth rather than individual owners' abilities. Real-world data verification is encouraged.
FRONTIERS IN PHYSICS
(2023)
Article
Astronomy & Astrophysics
Luiz L. Lopes, H. C. Das
Summary: In this study, we investigate the properties of strange quark stars mixed with dark matter. We examine the effects of dark matter on the macroscopic characteristics of strange stars, such as their maximum masses, radii, and dimensionless tidal parameters. Our findings show that the macroscopic properties strongly depend on the mass, type, and fraction of dark matter within the star.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Seongjin Ahn, S. Das Sarma
Summary: By investigating the quasiparticle properties of a two-dimensional electron gas, we identified anisotropic features that are not captured by commonly used isotropic approximations. Our theory provides a more accurate description of the properties of anisotropic systems and highlights the inaccuracies that can arise from neglecting mass anisotropy. We also introduce new theoretical approaches that extend existing many-body theories to anisotropic systems.
Article
Chemistry, Physical
Jing Sun, Sudip Sasmal, Oriol Vendrell
Summary: The original Meyer-Miller Hamiltonian is applied to map fermionic quantum dynamics to classical equations of motion. For non-interacting systems, the Jordan-Wigner transform does not lead to any improvement in the performance of mappings for fermionic systems. The classical mappings are able to capture interference effects, both constructive and destructive, originating from equivalent energy transfer pathways in the models.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Astronomy & Astrophysics
Sambit K. Giri, Aurel Schneider
Summary: This paper investigates the potential of the 21-cm signal from the epoch of cosmic dawn to constrain mixed dark matter scenarios. It shows how the scenarios affect the global signal and power spectrum and provides constraints on the mass and fraction of noncold dark matter.
Review
Multidisciplinary Sciences
Luca Salasnich, Alberto Cappellaro, Koichiro Furutani, Andrea Tononi, Giacomo Bighin
Summary: We review the theoretical results of sound propagation in two-dimensional systems of ultracold fermionic and bosonic atoms. We discuss the coexistence of first and second sound in the superfluid phase and present models for sound velocity measurements in weakly-interacting regimes. Our calculations accurately compute superfluid density and show consistency with experimental results. Additionally, we calculate sound velocities in the BCS-BEC crossover and predict sound mode mixing in the finite-temperature BEC regime.
Article
Physics, Multidisciplinary
B. Gremaud, G. G. Batrouni
Summary: The study uses computational methods to investigate the onset and properties of pair superfluidity in various systems with interspecies attraction, showing that pairs are the sole contributors to superfluidity under attractive interactions and this crucial property is often overlooked in previous studies.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Physical
Evgenii Sterkhov, Nikolay M. Chtchelkatchev, Elena Mostovshchikova, Roman E. Ryltsev, Sergey A. Uporov, Gheorghe L. Pascut, Andrey Fetisov, Svetlana G. Titova
Summary: PrBaMn2O6 with ordered alternate stacking of PrMnO3/BaMnO3 layers exhibits two magnetic phase transitions close to room temperature, making it a promising magnetocaloric and magnetoresistive material. The experimentally detected structural transition is attributed to the splitting of eg-doublet states due to the tendency towards orbital ordering at the metal-insulator phase transition.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
S. A. Uporov, R. E. Ryltsev, V. A. Sidorov, S. Kh Estemirova, E. Sterkhov, I. A. Balyakin, N. M. Chtchelkatchev
Summary: The study explores the pressure effects on the electronic structure and electrical conductivity of TiZrHfNb alloy. It shows that the resistance of the alloy decreases linearly by 12.5% as the pressure increases to 5.5 GPa and is mainly determined by residual resistance and Mott's s-d scattering. The alloy is a Curie-Weiss paramagnet and a type-II superconductor with a critical temperature of about 6.3 K.
Article
Chemistry, Physical
I. Sterkhova, L. Kamaeva, N. M. Chtchelkatchev, V. Lad'yanov
Summary: The study investigates the influence of carbon concentration on phase equilibria, crystallization processes, and structure of Fe-Cr-C alloys, revealing the minimum undercoolability at around 14% C and a decrease in microhardness with increasing carbon concentration. The nonequilibrium crystallization is found to be related to the peculiarities of interatomic interaction in the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Multidisciplinary
V. A. Levashov, R. E. Ryltsev, N. M. Chtchelkatchev
Summary: This study investigates the local structural similarity between the parent-liquid and children-crystal states in a model soft-matter system, revealing that at different pressures the system crystallizes into significantly different structures. The results demonstrate the importance of orientational ordering in understanding the behavior of liquids and the crystallization process.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2022)
Article
Materials Science, Multidisciplinary
I. P. Zibrova, V. P. Filonenkoa, V. A. Sidorova, N. M. Chtchelkatcheva, M. V. Magnitskayaa
Summary: A new high-pressure modification, VO2(S), was obtained by thermobaric treatment of a stoichiometric mixture of V2O3 + V2O5 powders. The crystal structure of VO2(S) is double-layered, with distorted VO6 octahedra as the structural units. It undergoes a weak first-order phase transition. The charge and heat transport properties were evaluated through density functional calculations and the semiclassical Boltzmann approach.
Article
Chemistry, Physical
Sergey V. Streltsov, Roman E. Ryltsev, Nikolay M. Chtchelkatchev
Summary: In recent years, the A-site ordered half-doped double-perovskite manganites RBaMn2O6 have gained significant attention for their exceptional physical properties and potential applications. This study investigates the origin of the ground-state structure and the electronic and magnetic properties of PrBaMn2O6. The findings offer insights into understanding the contradictions in experimental data and provide a theoretical foundation for refining the ground state structures in other RBaMn2O6 compounds.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Condensed Matter
L. Kamaeva, M. Magnitskaya, A. A. Suslov, A. Tsvyashchenko, N. M. Chtchelkatchev
Summary: In this study, the stability and phase transitions of the non-equilibrium B20-RhGe phase, which can only be obtained under high pressure, were investigated using ab initio calculations and experimental methods. The results revealed the thermal stability and heating-induced phase transformations of RhGe samples, and were validated by calorimetric measurements and X-ray diffraction analysis.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Physics, Condensed Matter
R. E. Ryltsev, N. M. Chtchelkatchev
Summary: Two-length-scale pair potentials in condensed matter systems lead to complex behavior, and we find that different two-length-scale systems with similar radial distribution functions exhibit the same freezing behavior. By validating the similarity between two dimensionless parameters, we propose a method to predict the formation of solid phases.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
D. O. Skanchenko, E. V. Altynbaev, V. A. Sidorov, G. Chaboussant, N. Martin, A. E. Petrova, D. A. Salamatin, S. V. Grigoriev, N. M. Chtchelkatchev, M. V. Magnitskaya, A. V. Tsvyaschenko
Summary: We conducted a comprehensive study on Fe1-xRhxGe compounds, covering the entire concentration range using various techniques. We discovered an internal splitting of crystallographic and magnetic states for intermediate compositions, despite their apparent similarity. Theoretical analysis and experimental data revealed that this splitting occurs within single crystallites with a common space group, but with different magnetic structures.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Multidisciplinary
N. M. Chtchelkatchev, R. E. Ryltsev, A. V. Mikheyenkov, V. E. Valiulin, I. Ya. Polishchuk
Summary: A general problem in studying supercooled liquids and glasses is the long relaxation times that make it difficult to determine dynamic characteristics explicitly. To solve this issue, one approach is to extrapolate values of a dynamical property, such as viscosity, from a temperature range where it can be directly measured or simulated to the low-temperature region. However, such extrapolations often lead to contradictory results due to different fitting functions. This paper proposes a model-free statistical algorithm for low-temperature extrapolation of liquid viscosity and diffusion coefficient, utilizing numerical analytical continuation and error correction procedures. The method has been tested on various glass-forming systems and showed good stability and predictability.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
S. G. Menshikova, N. M. Chtchelkatchev, V. V. Brazhkin
Summary: High pressures enable the synthesis of new metastable compounds that remain intact under normal conditions. In this study, we investigated the structure of a glass-forming eutectic alloy obtained through rapid cooling from the melt at a temperature of 1800 K and a pressure of 10 GPa. Our findings reveal the formation of new stable crystalline phases with cubic and tetragonal structures in the alloy.
Article
Physics, Multidisciplinary
Valerii E. Valiulin, Andrey V. V. Mikheyenkov, Nikolay M. Chtchelkatchev, Kliment I. Kugel
Summary: The Kugel-Khomskii model, which involves spin and orbital degrees of freedom, serves as a useful tool for studying important aspects of quantum information processing, such as robust gaps in entanglement spectra. In this study, we demonstrate that entanglement can remain robust even under temperature effects within a wide range of parameters. Interestingly, the temperature dependence of entanglement often exhibits a nonmonotonic behavior, with ranges of model parameters where entanglement is absent at zero temperature, but emerges, reaches a maximum, and then disappears with increasing temperature.
SCIPOST PHYSICS CORE
(2023)
Article
Chemistry, Physical
N. M. Chtchelkatchev, R. E. Ryltsev, M. V. Magnitskaya, S. M. Gorbunov, K. A. Cherednichenko, V. L. Solozhenko, V. V. Brazhkin
Summary: Boron phosphide (BP) is a hard semiconductor composed of light elements and has potential applications under extreme conditions. The behavior of BP at high temperatures and pressures is not well understood, but machine learning interatomic potentials provide a unique opportunity to study it accurately. A deep machine learning potential (DP) has been developed for accurate simulations of BP, which agrees with experimental and ab initio molecular dynamics data. The simulations reveal structural transformations and anomalous behavior of BP under compression and raise open questions for further studies.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Aleksandra Petkovic, Zoran Ristivojevic
Summary: We study the motion of a heavy impurity in a one-dimensional Bose gas. The impurity experiences a friction force due to scattering off thermally excited quasiparticles. We present a detailed analysis of an arbitrarily strong impurity-boson coupling in a wide range of temperatures within a microscopic theory and derive an analytical result for the friction force, uncovering new regimes of impurity dynamics. Particularly interesting is the low-temperature T2 dependence of the friction force obtained for a strongly coupled impurity, which should be contrasted with the expected T4 scaling. Furthermore, we investigate the evolution of the impurity with a given initial momentum and evaluate its nonstationary momentum distribution function analytically, finding that the impurity relaxation towards equilibrium follows the Ornstein-Uhlenbeck process in momentum space.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Aleksandra Petkovic
Summary: This study investigates a weakly interacting Bose gas with a single static impurity in one dimension, assuming that the phase coherence length is longer than the system size. An analytic expression for the local spectral density valid for positive strengths of the impurity coupling to the bosons at all distances and frequencies is obtained using the Bogoliubov-de Gennes approximation.