138 research outputs found

    Spin polarized states in neutron matter at a strong magnetic field

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    Spin polarized states in neutron matter at a strong magnetic field are considered in the model with the Skyrme effective interaction (SLy4, SLy7 parametrizations). Analyzing the self-consistent equations at zero temperature, it is shown that a thermodynamically stable branch of solutions for the spin polarization parameter as a function of density corresponds to the negative spin polarization when the majority of neutron spins are oriented oppositely to the direction of the magnetic field. Besides, beginning from some threshold density being dependent on the magnetic field strength the self-consistent equations have also two other branches (upper and lower) of solutions for the spin polarization parameter with the positive spin polarization. The free energy corresponding to the upper branch turns out to be very close to the free energy corresponding to the thermodynamically preferable branch with the negative spin polarization. As a consequence, at a strong magnetic field, the state with the positive spin polarization can be realized as a metastable state at the high density region in neutron matter which under decreasing density at some threshold density changes into a thermodynamically stable state with the negative spin polarization. The calculations of the neutron spin polarization parameter and energy per neutron as functions of the magnetic field strength show that the influence of the magnetic field remains small at the field strengths up to 101710^{17} G.Comment: Prepared with RevTeX4, 8pp., 5 figs; v.2: matches published versio

    Finite temperature effects in antiferromagnetism of nuclear matter

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    The influence of the finite temperature on the antiferromagnetic (AFM) spin ordering in symmetric nuclear matter with the effective Gogny interaction is studied within the framework of a Fermi liquid formalism. It is shown that the AFM spin polarization parameter of partially polarized nuclear matter for low enough temperatures increases with temperature. The entropy of the AFM spin state for some temperature range is larger than the entropy of the normal state. Nerveless, the free energy of the AFM spin state is always less than the free energy of the normal state and, hence, the AFM spin polarized state is preferable for all temperatures below the critical temperature.Comment: To appear in PRC; some references and comments adde

    Unusual temperature behavior of entropy of antiferromagnetic spin state in nuclear matter with effective finite range interaction

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    The unusual temperature behavior of the entropy of the antiferromagnetic (AFM) spin state in symmetric nuclear matter with the Gogny D1S interaction, being larger at low temperatures than the entropy of nonpolarized matter, is related to the dependence of the entropy on the effective masses of nucleons in a spin polarized state. The corresponding conditions for comparing the entropies of the AFM and nonpolarized states in terms of the effective masses are formulated, including low and high temperature limits. It is shown that the unexpected temperature behavior of the entropy of the AFM spin state at low temperatures is caused by the violation of the corresponding low temperature criterium.Comment: version accepted for publication in PR

    Phase transition to the state with nonzero average helicity in dense neutron matter

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    The possibility of the appearance of the states with a nonzero average helicity in neutron matter is studied in the model with the Skyrme effective interaction. By providing the analysis of the self-consistent equations at zero temperature, it is shown that neutron matter with the Skyrme BSk18 effective force undergoes at high densities a phase transition to the state in which the degeneracy with respect to helicity of neutrons is spontaneously removed.Comment: 4 pages, 3 figures; v2: journal versio

    Spin polarized states in strongly asymmetric nuclear matter

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    In the framework of a Fermi liquid theory it is considered the possibility of appearance of spin polarized states in strongly asymmetric nuclear matter with Skyrme effective interaction. The zero temperature dependence of neutron and proton spin polarization parameters as functions of density is found for SLy4, SLy5 effective forces. It is shown that at some critical density it will be formed the state with the oppositely directed spins of neutrons and protons, while the state with the same direction of spins does not appear. In comparison with neutron matter, even small admixture of protons strongly decreases the threshold density of spin instability. It is clarified that protons become totally polarized within very narrow density domain while in the density profile of neutron spin polarization parameter their appear long tails near the transition density.Comment: Prepared with RevTeX4, 8p., 3 figures; to appear in PR

    Anisotropic multi-gap superfluid states in nuclear matter

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    It is shown that under changing density or temperature a nucleon Fermi superfluid can undergo a phase transition to an anisotropic superfluid state, characterized by nonvanishing gaps in pairing channels with singlet-singlet (SS) and triplet-singlet (TS) pairing of nucleons (in spin and isospin spaces). In the SS pairing channel nucleons are paired with nonzero orbital angular momentum. Such two-gap states can arise as a result of branching from the one-gap solution of the self-consistent equations, describing SS or TS pairing of nucleons, that depends on the relationship between SS and TS coupling constants at the branching point. The density/temperature dependence of the order parameters and the critical temperature for transition to the anisotropic two-gap state are determined in a model with the SkP effective interaction. It is shown that the anisotropic SS-TS superfluid phase corresponds to a metastable state in nuclear matter.Comment: Prepared with RevTeX4, 7p., 5 fi

    TRANSFER OF ELECTRIC CHARGE THROUGH Al-Se95Te5-Te STRUCTURE

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    It is established that current passing through Al-Se95Te5<Sm>-Te structures is carried out by monopolar injection mechanism at participation of traps for holes. It is shown that the doping by samarium strongly influences on the current flow mechanism in the investigated structure due to changes in the energy spectrum of the local states.The local level parameters (concentration and energy state) controlling the electric charge transfer are defined with the use of existing theories of injection currents

    The application of legal-statistical method in analysing manufacturing property’s institutional development

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    Purpose: The study defines the specifics and opportunities, that arise due to the application of statistical method in judicial research of manufacturing property. Design/Methodology/Approach: The authors put the ground of the study on the aggregation of a vast spectrum of statistical data and indicators of patent activity of leading countries in the sphere of technological innovation. Findings: The authors outlined the main tendencies of legal regulation of scientific and artistic results of intellectual property development and define the specifics and opportunities that arise due to the application of statistical method in judicial research of manufacturing property. Lack of coordination of approaches to protect manufacturing property on the international level, obstructs the development of patent activity amongst the members of the Paris Convention and significantly reduces the effectiveness of the current patent system. Practical implications: Authors' development could be utilized in future developments of Russian institute of manufacturing property and its legal framework. Originality/Value: The contribution of the article is the comprehensive analysis of legal background of intellectual property institute and its development prospects.peer-reviewe
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