scholarly journals Entangling Lattice-Trapped Bosons with a Free Impurity: Impact on Stationary and Dynamical Properties

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 290
Author(s):  
Maxim Pyzh ◽  
Kevin Keiler ◽  
Simeon I. Mistakidis ◽  
Peter Schmelcher
Keyword(s):  
Structural Changes ◽  
Many Body ◽  
Wide Range ◽  
Entropy Measures ◽  
Particle Level ◽  
The Many ◽  
The One ◽  
Tunneling Dynamics ◽  
The Individual ◽  
Trapped Bosons

We address the interplay of few lattice trapped bosons interacting with an impurity atom in a box potential. For the ground state, a classification is performed based on the fidelity allowing to quantify the susceptibility of the composite system to structural changes due to the intercomponent coupling. We analyze the overall response at the many-body level and contrast it to the single-particle level. By inspecting different entropy measures we capture the degree of entanglement and intraspecies correlations for a wide range of intra- and intercomponent interactions and lattice depths. We also spatially resolve the imprint of the entanglement on the one- and two-body density distributions showcasing that it accelerates the phase separation process or acts against spatial localization for repulsive and attractive intercomponent interactions, respectively. The many-body effects on the tunneling dynamics of the individual components, resulting from their counterflow, are also discussed. The tunneling period of the impurity is very sensitive to the value of the impurity-medium coupling due to its effective dressing by the few-body medium. Our work provides implications for engineering localized structures in correlated impurity settings using species selective optical potentials.

Many-body Green functions in nuclear physics

2017 ◽  
Vol 26 (01n02) ◽  
pp. 1740025 ◽  
Author(s):  
J. Speth ◽  
N. Lyutorovich
Keyword(s):  
Nuclear Physics ◽  
Green Functions ◽  
Many Body ◽  
General Applicability ◽  
Pair Correlations ◽  
Self Consistent ◽  
The Many ◽  
The One ◽  
General Relations ◽  
Three Body

Many-body Green functions are a very efficient formulation of the many-body problem. We review the application of this method to nuclear physics problems. The formulas which can be derived are of general applicability, e.g., in self-consistent as well as in nonself-consistent calculations. With the help of the Landau renormalization, one obtains relations without any approximations. This allows to apply conservation laws which lead to important general relations. We investigate the one-body and two-body Green functions as well as the three-body Green function and discuss their connection to nuclear observables. The generalization to systems with pair correlations are also presented. Numerical examples are compared with experimental data.

Elemental Interfaces and Displacive Phase Transformations

2008 ◽  
Vol 59 ◽  
pp. 63-68
Author(s):  
Václav Paidar
Keyword(s):  
Phase Transformations ◽  
Structural Changes ◽  
Atomic Plane ◽  
Many Body ◽  
Single Plane ◽  
Atomistic Models ◽  
Shear Type ◽  
Hcp Structure ◽  
The Many

Two basic processes, namely shear and shuffling of atomic planes can be considered as elementary mechanisms of displacive phase transformations. The atomistic models suitable to investigate the role of interfaces in the structural changes are tested. The many-body potentials are used for the description of interatomic forces. General displacements of atomic planes are examined, i.e. γ-surface type calculations extensively used for stacking fault and lattice dislocation analysis are applied to single plane shuffling and alternate shuffling of every other atomic plane producing in combination with homogeneous deformation the hcp structure. Similar approach considering shear type planar displacements leads to the Zener path between the bcc and fcc lattices. The effect of additional deformation required to obtain the close-packed atomic arrangements is analysed.

scholarly journals Impact of the transverse direction on the many-body tunneling dynamics in a two-dimensional bosonic Josephson junction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anal Bhowmik ◽  
Sudip Kumar Haldar ◽  
Ofir E. Alon
Keyword(s):  
Josephson Junction ◽  
Quantum Dynamics ◽  
Transverse Direction ◽  
General Rule ◽  
Time Dependent ◽  
Two Dimensional ◽  
Many Body ◽  
Initial State ◽  
The Many ◽  
Tunneling Dynamics

AbstractTunneling in a many-body system appears as one of the novel implications of quantum physics, in which particles move in space under an otherwise classically-forbidden potential barrier. Here, we theoretically describe the quantum dynamics of the tunneling phenomenon of a few intricate bosonic clouds in a closed system of a two-dimensional symmetric double-well potential. We examine how the inclusion of the transverse direction, orthogonal to the junction of the double-well, can intervene in the tunneling dynamics of bosonic clouds. We use a well-known many-body numerical method, called the multiconfigurational time-dependent Hartree for bosons (MCTDHB) method. MCTDHB allows one to obtain accurately the time-dependent many-particle wavefunction of the bosons which in principle entails all the information of interest about the system under investigation. We analyze the tunneling dynamics by preparing the initial state of the bosonic clouds in the left well of the double-well either as the ground, longitudinally or transversely excited, or a vortex state. We unravel the detailed mechanism of the tunneling process by analyzing the evolution in time of the survival probability, depletion and fragmentation, and the many-particle position, momentum, and angular-momentum expectation values and their variances. As a general rule, all objects lose coherence while tunneling through the barrier and the states which include transverse excitations do so faster. In particular for the later states, we show that even when the transverse direction is seemingly frozen, prominent many-body dynamics in a two-dimensional bosonic Josephson junction occurs. Implications are briefly discussed.

scholarly journals Many-body effects in semiconducting single-wall silicon nanotubes

2014 ◽  
Vol 5 ◽  
pp. 19-25 ◽  
Author(s):  
Wei Wei ◽  
Timo Jacob
Keyword(s):  
Binding Energies ◽  
Band Gaps ◽  
Many Body ◽  
Nanoscale Device ◽  
Strong Electron ◽  
Self Energy ◽  
Silicon Nanotubes ◽  
Particle Level ◽  
The Many ◽  
Silicon Based

The electronic and optical properties of semiconducting silicon nanotubes (SiNTs) are studied by means of the many-body Green’s function method, i.e., GW approximation and Bethe–Salpeter equation. In these studied structures, i.e., (4,4), (6,6) and (10,0) SiNTs, self-energy effects are enhanced giving rise to large quasi-particle (QP) band gaps due to the confinement effect. The strong electron−electron (e−e) correlations broaden the band gaps of the studied SiNTs from 0.65, 0.28 and 0.05 eV at DFT level to 1.9, 1.22 and 0.79 eV at GW level. The Coulomb electron−hole (e−h) interactions significantly modify optical absorption properties obtained at noninteracting-particle level with the formation of bound excitons with considerable binding energies (of the order of 1 eV) assigned: the binding energies of the armchair (4,4), (6,6) and zigzag (10,0) SiNTs are 0.92, 1.1 and 0.6 eV, respectively. Results in this work are useful for understanding the physics and applications in silicon-based nanoscale device components.

STRUCTURAL PROPERTIES OF BIMETALLIC CLUSTERS FROM DENSITY FUNCTIONAL CALCULATIONS

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2339-2344 ◽  
Author(s):  
EVA M. FERNÁNDEZ ◽  
LUIS C. BALBÁS ◽  
LUIS A. PÉREZ ◽  
KARO MICHAELIAN ◽  
IGNACIO L. GARZÓN
Keyword(s):  
Structural Properties ◽  
Density Functional ◽  
Geometry Optimization ◽  
Model Potential ◽  
Bimetallic Clusters ◽  
Many Body ◽  
Generalized Gradient ◽  
The Many ◽  
The One ◽  
Gupta Potential

The structural properties and energy ordering of the lowest lying isomers of bimetallic ( CuAu )n and ( PtPd )n, n=5-22 clusters have been investigated by means of density functional theory (DFT) in the generalized gradient approximation (GGA). The initial cluster geometry optimization is performed by using a genetic algorithm with the many body Gupta potential. This technique provide a distribution of the lowest energy cluster structures, that are further reoptimized using the DFT-GGA methodology. The energy ordering of isomers obtained with the Gupta potential does not agree, in general, with the one obtained using DFT-GGA for the two bimetallic clusters investigated. However, the lowest energy strucutures of the ( CuAu )n nanoalloy show icosahedral patterns in agreement with the results obtained with the model potential. For the ( PtPd )n clusters segregation effects are found, where the Pt atoms are forming the cluster core and the Pd atoms are on the cluster surface, in agreement with previous calculations using the many body Gupta potential.

scholarly journals On the question of the functions and tasks of legal custom

2020 ◽  
pp. 30-34
Author(s):  
Marian Bedrii
Keyword(s):  
Social Relations ◽  
Legal System ◽  
Legal Protection ◽  
Legal Regulation ◽  
Protective Function ◽  
Current State ◽  
Wide Range ◽  
The Subject ◽  
The One ◽  
The Individual

The article researches the functions and tasks of legal custom based on historical experience and the current state of legal life.The view represents that law and culture functions are realized through legal custom, as it is an important element of these phenomena.At the same time, it is noted that legal custom is characterized by a separate catalog of functions and tasks that need to be studied. Theregulatory, explanatory, protective, defensive, inflectional, reconstitutive, ideological-educative, identification-communicative, antimonopoly,and legal-resource functions of legal custom are analyzed. The administrative and organizational components of the regulatoryfunction of legal custom are highlighted. The preventive and restrictive components of the protective function of legal custom are cha -racterized. It is substantiated that these functions are inextricably linked with the tasks of legal custom.Based on the analyzed functions, the following tasks of a legal custom are allocated: the legal regulation of social relations; cla -rification of provisions of the legislation, acts of law enforcement, texts of agreements, terms and symbolic actions; legal protection ofpublic goods and values; providing opportunities to protect rights and freedoms; stabilization of the legal system, its protection fromill-considered and risky transformations; reproduction of the acquired legal experience in new conditions; ensuring the flexibility of thelegal system; influence on the worldview of the individual and society in general; determining the affiliation of the subject to a parti -cular community and maintaining communication between its members; prevention of monopoly in the legal system of a normativelegal act or other sources of law; formation of material for the systematization of law.It is argued that legal custom, as a social phenomenon, evolving in the process of history, performed a wide range of functionsthat correlated with its tasks. Not every period, people, or locality is characterized by a full set of analyzed functions and tasks, but itis worth noting the possibility of their implementation by the legal custom in general, as evidenced by past experience and the currentstate of legal relations. The results of the research, on the one hand, complement the understanding of the nature of legal custom, andon the other – prove the feasibility of further use of this source of law in modern legal systems.

The Position of the Insurance Press in relation to Insurance Offices and Insurance Interests

1881 ◽  
Vol 23 (1) ◽  
pp. 18-28
Author(s):  
Cornelius Walford
Keyword(s):  
The Other ◽  
Individual Responsibility ◽  
The Press ◽  
The Subject ◽  
The Many ◽  
The One ◽  
The Individual

I think the time has arrived when the subject indicated in the title of this paper may be fairly and fully considered. It is certainly one which must frequently have presented itself to the managerial mind; and there can be no reason why this question should not be discussed with as much philosophic calmness as any of the many theoretical problems, or points in practice, which continually present themselves for reflection, and perchance for decision.The point may indeed arise—whether I am the proper person to introduce the topic. I take the individual responsibility of deciding in the affirmative. I have, on the one hand, been as frequently assailed by the insurance press, as any one, and, on the other, received as much kindness and friendly recognition as any man can desire, and more than I claim to deserve. It may be that in either case the extreme has been reached, or passed. I have the advantage of having been a writer upon the press, insurance and general, from the days of my youth, and I say at once that my sympathies are largely on that side. But I think that the familiarity which draws me to the side of its virtues, also renders me, at least in some degree, cognizant of its short-comings. I have the further advantage of having been on various occasions consulted by managers on the one hand, and by editors on the other, upon the points which I now proceed to discuss.

The Large Novel and the Law of Large Numbers: Daniel Deronda and the Counterintuitive

Good Form ◽  
2019 ◽  
pp. 153-190
Author(s):  
Jesse Rosenthal
Keyword(s):  
Statistical Significance ◽  
Individual Case ◽  
Human Interaction ◽  
Daniel Deronda ◽  
Large Numbers ◽  
Conceptual Shift ◽  
State Of Affairs ◽  
The Many ◽  
The One ◽  
The Individual

This chapter assesses the counterintuitive: the ending that “feels wrong,” or that does not work out as it seems it should. Certainly, this could mean many things, from a poorly constructed novel to the pedagogy implied by naturalist accident. The form of the counterintuitive that structures much of George Eliot's Daniel Deronda (1876), however, and which enacts the novel's stern moral lesson, develops from Eliot's more social concerns. Eliot, throughout her writing career, worked with an idea of narrative intuition, and formal morality, connected with the model consisting of a working out of the identity between an individual and the larger group. In Deronda, though, with its consistent concentration on ideas of probability and statistical significance, one sees a conceptual shift in Eliot's thinking about the relation of the one and the many. In short: though the larger workings of human interaction indicate that a certain state of affairs shall certainly come about at the largest levels, this offers no indication of how or when this might resolve in the individual case.

On Permanent Rotations of a System of Two Coupled Gyrostats in a Central Newtonian Force Field

2015 ◽  
Author(s):  
Dmitriy Chebanov ◽  
Jose A. Salas
Keyword(s):  
Force Field ◽  
Vertical Axis ◽  
Many Body ◽  
Newtonian Force ◽  
Body Dynamics ◽  
A Chain ◽  
The Many ◽  
The One ◽  
Permanent Rotations ◽  
Newtonian Force Field

This paper studies the problem of the motion of a chain of two gyrostats coupled by an ideal spherical joint. The chain moves about a fixed point in a central Newtonian force field. Under the assumption that the gyrostatic moment of each gyrostat is constant relative to its carrier, the paper establishes and analyzes the conditions for existence of the chain’s permanent rotations about a vertical axis. For a case when each gyrostat has the mass distribution analogous to the one of a Lagrange gyroscope, the paper derives and analyzes the necessary conditions for stability of the permanent rotations. The findings of the paper extend corresponding results in the dynamics of a single gyrostat to a case of the multibody chain as well as generalize some of the known properties of permanent rotations in the many-body dynamics.

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