scholarly journals COLOUR SUPERCONDUCTIVITY IN FINITE SYSTEMS

2003 ◽  
Vol 17 (28) ◽  
pp. 5185-5189
Author(s):  
P. AMORE ◽  
M. C. BIRSE ◽  
J. A. MCGOVERN ◽  
N. R. WALET
Keyword(s):  
Superconducting State ◽  
Singlet State ◽  
Finite Size ◽  
Baryon Number ◽  
The State ◽  
Finite Systems ◽  
Colour Singlet ◽  
Group Manifold ◽  
Colour Group

We have studied the effects of finite size on the two flavor colour superconducting state. Since the baryon number in the BCS state is only fixed on average, we have projected the state over a fixed baryon number. The resulting state has been then projected over a colour-singlet state, by integrating over the colour group manifold. The effects of both projections have been evaluated numerically.

scholarly journals Geometries and Electronic States of Divacancy Defect in Finite-Size Hexagonal Graphene Flakes

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Lili Liu ◽  
Shimou Chen
Keyword(s):  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Singlet State ◽  
Tight Binding ◽  
Finite Size ◽  
Electronic States ◽  
Closed Shell ◽  
Graphene Flakes ◽  
Self Consistent

The geometries and electronic properties of divacancies with two kinds of structures were investigated by the first-principles (U) B3LYP/STO-3G and self-consistent-charge density-functional tight-binding (SCC-DFTB) method. Different from the reported understanding of these properties of divacancy in graphene and carbon nanotubes, it was found that the ground state of the divacancy with 585 configurations is closed shell singlet state and much more stable than the 555777 configurations in the smaller graphene flakes, which is preferred to triplet state. But when the sizes of the graphene become larger, the 555777 defects will be more stable. In addition, the spin density properties of the both configurations are studied in this paper.

EPR Elements of Physical Reality in Quantum Mechanics

1997 ◽  
Vol 12 (29) ◽  
pp. 5289-5303
Author(s):  
V. K. Thankappan ◽  
Ravi K. Menon
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Singlet State ◽  
Physical Reality ◽  
The State ◽  
Wave Functions ◽  
Definition Of

The concept of elements of physical reality (e.p.r.) in quantum mechanics as defined by Einstein, Podolsky and Rosen (EPR) is discussed in the context of the EPR–Bohm and the EPR–Bell experiments on a pair of spin 1/2 particles in the singlet state. It is argued that EPR's definition of e.p.r. is appropriate to the EPR–Bell experiment rather than to the EPR–Bohm experiment, and that Bohr's interpretation of e.p.r. is also consistent with such a viewpoint. It is shown that the observed correlation between the spins of the two particles in the EPR–Bell experiment is just a manifestation of the correlation that exists between the wave functions of the particles in the singlet state and a consequence of the fact that a Stern–Gerlach magnet does not change the state of a particle but only transforms its wave function into a representation defined by the axis of the magnet. As such, the correlation is suggested to be an affirmation of Einstein's concept of locality, and not an evidence for nonlocality.

scholarly journals From Heavy-Ion Collisions to Compact Stars: Equation of State and Relevance of the System Size

Universe ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 14 ◽  
Author(s):  
Sylvain Mogliacci ◽  
Isobel Kolbé ◽  
W. Horowitz
Keyword(s):  
Equation Of State ◽  
Degrees Of Freedom ◽  
Compact Star ◽  
Relativistic Quantum ◽  
Finite Size ◽  
Baryon Number ◽  
System Size ◽  
Heavy Ion ◽  
Compact Stars ◽  
Heavy Ion Physics

In this article, we start by presenting state-of-the-art methods allowing us to compute moments related to the globally conserved baryon number, by means of first principle resummed perturbative frameworks. We focus on such quantities for they convey important properties of the finite temperature and density equation of state, being particularly sensitive to changes in the degrees of freedom across the quark-hadron phase transition. We thus present various number susceptibilities along with the corresponding results as obtained by lattice quantum chromodynamics collaborations, and comment on their comparison. Next, omitting the importance of coupling corrections and considering a zero-density toy model for the sake of argument, we focus on corrections due to the small size of heavy-ion collision systems, by means of spatial compactifications. Briefly motivating the relevance of finite size effects in heavy-ion physics, in opposition to the compact star physics, we present a few preliminary thermodynamic results together with the speed of sound for certain finite size relativistic quantum systems at very high temperature.

scholarly journals Kirkwood-Buff Integrals Using Molecular Simulation: Estimation of Surface Effects

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 771 ◽  
Author(s):  
Noura Dawass ◽  
Peter Krüger ◽  
Sondre K. Schnell ◽  
Othonas A. Moultos ◽  
Ioannis G. Economou ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Thermodynamic Limit ◽  
Finite Size ◽  
Surface Effects ◽  
System Size ◽  
Distribution Functions ◽  
Finite Systems ◽  
System Method ◽  
The One ◽  
The Relationship

Kirkwood-Buff (KB) integrals provide a connection between microscopic properties and thermodynamic properties of multicomponent fluids. The estimation of KB integrals using molecular simulations of finite systems requires accounting for finite size effects. In the small system method, properties of finite subvolumes with different sizes embedded in a larger volume can be used to extrapolate to macroscopic thermodynamic properties. KB integrals computed from small subvolumes scale with the inverse size of the system. This scaling was used to find KB integrals in the thermodynamic limit. To reduce numerical inaccuracies that arise from this extrapolation, alternative approaches were considered in this work. Three methods for computing KB integrals in the thermodynamic limit from information of radial distribution functions (RDFs) of finite systems were compared. These methods allowed for the computation of surface effects. KB integrals and surface terms in the thermodynamic limit were computed for Lennard–Jones (LJ) and Weeks–Chandler–Andersen (WCA) fluids. It was found that all three methods converge to the same value. The main differentiating factor was the speed of convergence with system size L. The method that required the smallest size was the one which exploited the scaling of the finite volume KB integral multiplied by L. The relationship between KB integrals and surface effects was studied for a range of densities.

HOW MONTE CARLO SIMULATIONS CAN CLARIFY COMPLEX PROBLEMS IN STATISTICAL PHYSICS

2001 ◽  
Vol 15 (09) ◽  
pp. 1193-1211 ◽  
Author(s):  
KURT BINDER
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Statistical Physics ◽  
Condensed Matter ◽  
Finite Size ◽  
Two Dimensional ◽  
Finite Size Scaling ◽  
Complex Phase ◽  
Finite Systems ◽  
Scaling Methods

Statistical mechanics of condensed matter systems in physics (fluids and solids) derives macroscopic equilibrium properties of these systems as averages computed from a Hamiltonian that describes the atomistic interactions in the system. While analytic methods for most problems involve uncontrolled approximations, Monte Carlo simulations allow numerically exact treatments, apart from statistical errors and from the systematic problem that finite systems are treated rather than the thermodynamic limit. However, this problem can be overcome by finite size scaling methods, and thus Monte Carlo methods have become a very powerful tool to study even complex phase transitions. Examples given will include unmixing of polymer blends, two-dimensional melting, etc.

scholarly journals STABILITY OF COLOR-FLAVOR LOCKED STRANGELETS

2006 ◽  
Vol 21 (13n14) ◽  
pp. 3021-3030 ◽  
Author(s):  
O. KIRIYAMA
Keyword(s):  
Size Effects ◽  
Thermodynamic Potential ◽  
Finite Size ◽  
Baryon Number ◽  
Critical Value ◽  
Coupling Constant ◽  
Finite Size Effects ◽  
Quark Coupling ◽  
The Stability ◽  
Quark Flavors

The stability of color-flavor locked (CFL) strangelets is studied in the three-flavor Nambu–Jona-Lasinio model. We consider all quark flavors to be massless, for simplicity. By making use of the multiple reflection expansion, we explicitly take into account finite size effects and formulate the thermodynamic potential for CFL strangelets. We find that the CFL gap could be large enough so that the energy per baryon number of CFL strangelets is greatly affected. In addition, if the quark–quark coupling constant is larger than a certain critical value, there is a possibility of finding absolutely stable CFL strangelets.

Magnetic States and Frustrations of Square Spin Ice in 2D XY Point Dipoles Model

2016 ◽  
Vol 247 ◽  
pp. 148-152 ◽  
Author(s):  
Yuriy Shevchenko ◽  
Konstantin V. Nefedev
Keyword(s):  
Magnetic Moments ◽  
Finite Size ◽  
Xy Model ◽  
Spin Ice ◽  
Range Interaction ◽  
Finite Systems ◽  
Long Range Interaction ◽  
Average Size ◽  
Magnetic States ◽  
Ice Model

In the discrete 2D XY model of finite number of point dipoles of square spin ice, the order parameter has been calculated exactly as the average size of the maximal cluster. The finite size and edge effects do not allow research the critical behavior of the phase transition for finite systems. It is found that frustrations in spin ice model with long-range interaction are possible only in presence of symmetry for the distribution of magnetic moments.

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