World Journal of Condensed Matter Physics

Journal Information
ISSN / EISSN : 2160-6919 / 2160-6927
Published by: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 255
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Latest articles in this journal

Wajdi Michael Zoghaib, Carlo Carboni, Mohammed Elias Molla, Turkiya Al-Shahumi, Raya Al-Yazeedi
World Journal of Condensed Matter Physics, Volume 12, pp 27-37; https://doi.org/10.4236/wjcmp.2022.123004

Abstract:
Two new series (A & B) of three materials each based on the aroyl hydrazinato-nickel (II) complex were synthesized and characterized. The core molecule in these series consists of two 4-benzoyloxy benzylidene moieties and two benzene rings attached at the azomethine moiety. These latter benzene rings have one or two alkoxy chains comprised of either 10, 12, 16 or 18 carbon atoms. The characterization of these two series by polarized optical microscopy and differential scanning calorimetry is described herein. Upon cooling from the Isotropic phase, three of the six materials display a monophasic columnar phase and the other three possess a biphasic nematic and columnar phases. Upon heating, all six materials have a clearance point at high temperatures without displaying mesomorphic behavior. In series B mesogens, it was observed that the longer the hydrocarbon tail length, the lower the clearance point.
Fred J. Cadieu
World Journal of Condensed Matter Physics, Volume 12, pp 18-26; https://doi.org/10.4236/wjcmp.2022.122003

Abstract:
Correlations between the rotations of the terrestrial planets in our solar system and the magnetic field of the Sun have been previously noted. These correlations account for the opposite rotation of Venus as a result of the magnetic field of the Sun being dragged across the conducting core of Venus. Currently, the Sun’s magnetic field is not sufficiently strong to account for the proposed correlations. But recently meteorite paleomagnetism measurements have indicated that during the Sun’s formation the magnetic field of the Sun was of sufficient strength to have resulted in the observed correlations. Also, dating back to the Sun’s formation are measurements showing that the Sun’s core rotates four times faster than the Sun’s surface. Both the counter rotation of Venus and the initial period of strong Sun magnetic fields are believed to be relics of the time period when the Sun’s core to surface differential rotation was established. As a part of these correlations, it was hypothesized that for a terrestrial planet to exhibit a magnetosphere, the average density must be ≥5350 ± 50 kg/m3. On this basis, only the Earth and Mercury would have formed initial magnetospheres, while Venus, Mars, and the “Moon” would not have developed magnetospheres. For such correlations to still be present today requires our Sun to have been formed as a sole star and with what might be termed a friendly Jupiter. Otherwise, the observed correlations would have been disrupted over time.
Vilius Palenskis
World Journal of Condensed Matter Physics, Volume 12, pp 9-17; https://doi.org/10.4236/wjcmp.2022.122002

Abstract:
It is shown that the traditional explanation of the free electron properties, such as mean free electron path, drift mobility, and the relaxation time, by lattice vibrations, is not valid for real free randomly moving (RM) electrons in materials with degenerate electron gas. It is shown that the effective density of the free RM electrons in elemental metals is completely determined by density-of-states at the Fermi surface and by absolute temperature. The study has shown that the lattice vibrations excite not only the free RM electrons but also produce the same number of weakly screened ions (so-named electronic defects), which cause the scattering of the free RM electrons and related electron kinetic characteristics.
Wajdi Michael Zoghaib, Carlo Carboni, Mohammed Elias Molla, Samiya Al-Mahrezi, Turkiya Al-Shahumi, Sanaa Al-Badi, Muna Al-Farsi
World Journal of Condensed Matter Physics, Volume 12, pp 1-7; https://doi.org/10.4236/wjcmp.2022.121001

Abstract:
The mesogenic properties of a homologous series of aromatic ester materials are investigated. Single tail and double tail materials were synthesized to compare with other series we prepared and published earlier. The phase sequences and transition temperatures were obtained by polarized light microscopy and differential scanning calorimetry. Only the single tail materials with the ester attached to naphthalene at position 2 display mesogenicbehavior. Two materials (ZH 29 & ZH 32) possess a monophasic nematic phase and another two materials (ZH 14 & ZH 35) display biphasic nematic and smectic (A) phases.
Weihao Zhao
World Journal of Condensed Matter Physics, Volume 11, pp 65-76; https://doi.org/10.4236/wjcmp.2021.113005

Abstract:
Majorana fermions in two-dimensional systems satisfy non-Abelian statistics. They are possible to exist in topological superconductors as quasi particles, which is of great significance for topological quantum computing. In this paper, we study a new promising system of superconducting topological surface state topological insulator thin films. We also study the phase diagrams of the model by plotting the Majorana edge states and the density of states in different regions of the phase diagram. Due to the mirror symmetry of the topological surface states, the Hamiltonian can be block diagonalized into two spin-triplet p-wave superconductors, which are also confirmed by the phase diagrams. The chiral Majorana edge modes may provide a new route for realizing topological quantum computation.
Fred J. Cadieu
World Journal of Condensed Matter Physics, Volume 11, pp 13-27; https://doi.org/10.4236/wjcmp.2021.112002

Abstract:
The Sun comprises 99.9% of the solar system mass so it is expected that Sun terrestrial planet interactions can influence the motion as well as the rotation of the terrestrial planets. Gravity affects the planet orbital motions while the changing magnetic fields of the Sun can influence the planet rotations. Planets that manifest a magnetic field dominate any weaker magnetic fields from the Sun, but the rotation of terrestrial planets without a magnetic field interacts with the changing Sun’s field dependent on the electrical conductivity of the core region. It is determined that the average planet density becomes a useful quantity to describe the magnetic state of a terrestrial planet. An average density of 5350 ± 50 kg/m3 is hypothesized to separate planets that develop magnetospheres from those that do not. Planets with higher average densities, Mercury and Earth, developed magnetospheres. While those with lower average densities, Venus and Mars never developed magnetospheres. Terrestrial planets with magnetospheres are the ones to also exhibit plate tectonics. The small size of Mercury led to Mercury only exhibiting a frozen in magnetization of potentially magnetic regions. The lack of magnetospheres as well as lack of plate tectonics prevented the continual transfer of core heat to the surface that limited the surface vulcanism to an initial phase. For Venus, it meant that the surface regions would only sporadically convulse. In this picture, the apparent anomalous axial rotation of Venus is a natural consequence of the rotation of the Sun. For Mars with relatively low surface temperatures, it meant that there was little heat exchange through the crust that would allow the lower crust to retain large amounts of water. For Mars to have initially had flowing liquid water required that the atmosphere at that time contained high concentrations of infrared absorbing gases at least as compared to the present level of infrared absorbing gases on the Earth. The terrestrial planets have iron based cores because iron has the highest binding energy per nucleon that can be made in the steady state lives of massive stars no matter how massive. This suggests that many of the conclusions reached here may also be applicable to exoplanets.
Makokiyu Godlove Akumbom, Georges Collince Fouokeng, Martin Tchoffo, Lukong Cornelius Fai
World Journal of Condensed Matter Physics, Volume 11, pp 1-11; https://doi.org/10.4236/wjcmp.2021.111001

Abstract:
The behavior of liquids undergoing phase transition in the gravitational field is studied by considering the generalized Van der Waals equation. Considering the two simple models for liquid-vapor boundary of a pure classical fluid, the generalized Van der Waals equation shows how the three critical parameters (critical temperature, critical volume and critical pressure), suffice to describe the reduced state parameters (reduced temperature, reduced volume and reduced pressure), the concentration profile and the liquid-vapor boundary position, which can be used to observe transition phenomenon. This model shows how the form of the equation can influence the vertical phase separation induced by the stationary gravitational field, and on the gas condensation effects.
Anthony Twum, Raymond Edziah, Samuel Yeboah Mensah, Kwadwo Dompreh, Patrick Mensah-Amoah, Augustine Arthur, Natalia G. Mensah, Kofi Adu, George Nkrumah-Buandoh
World Journal of Condensed Matter Physics, Volume 11, pp 77-86; https://doi.org/10.4236/wjcmp.2021.114006

Abstract:
We have studied the axial resistivity of chiral single-walled carbon nanotubes (SWCNTs) in the presence of a combined direct current and high frequency alternating fields. We employed semiclassical Boltzmann equations approach and compared our results with a similar study that examined the circumferential resistivity of these unique materials. Our work shows that these materials display similar resistivity for both axial and circumferential directions and this largely depends on temperature, intensities of the applied fields and material parameters such as chiral angle. Based on these low-temperature bidirectional conductivity responses, we propose chiral SWCNTs for design of efficient optoelectronic devices.
Tomo Munehisa
World Journal of Condensed Matter Physics, Volume 11, pp 29-52; https://doi.org/10.4236/wjcmp.2021.113003

Abstract:
Entanglement in quantum theory is a concept that has confused many scientists. This concept implies that the cluster property, which means no relations between sufficiently separated two events, is non-trivial. In the works for some quantum spin systems, which have been recently published by the author, extensive and quantitative examinations were made about the violation of cluster property in the correlation function of the spin operator. The previous study of these quantum antiferromagnets showed that this violation is induced by the degenerate states in the systems where the continuous symmetry spontaneously breaks. Since this breaking is found in many materials such as the high temperature superconductors and the superfluidity, it is an important question whether we can observe the violation of the cluster property in them. As a step to answer this question we study a quantum nonlinear sigma model with U(1) symmetry in this paper. It is well known that this model, which has been derived as an effective model of the quantum spin systems, can also be applied to investigations of many materials. Notifying that the existence of the degenerate states is essential for the violation, we made numerical calculations in addition to theoretical arguments to find these states in the nonlinear sigma model. Then, successfully finding the degenerate states in the model, we came to a conclusion that there is a chance to observe the violation of cluster property in many materials to which the nonlinear sigma model applies.
Gulshan Prakash Malik, Vijaya Shankar Varma
World Journal of Condensed Matter Physics, Volume 11, pp 53-64; https://doi.org/10.4236/wjcmp.2021.113004

Abstract:
The empirically reported values of the critical current density (jc) of Bi-2212 as 2.4 × 105 (jc1; Sample 1) and 1.0 × 106 A/cm2 (jc2; Sample 2) are intriguing because both of them correspond to the same values of the temperature T = 4.2 K and the applied magnetic field H = 12 × 104 G. This difference is conventionally attributed to such factors—not all of which are quantifiable—as the geometry, dimensions and the nature of dopants and the manners of preparation of the samples which cause their granular structures, grain boundaries, alignment of the grains and so on to differ. Based on the premise that the chemical potential μ subsumes most of these features, given herein is a novel explanation of the said results in terms of the values of μ of the two samples. This paper revisits the problem that was originally addressed in [Malik G.P., Varma V.S. (2020) WJCMP, 10, 53-70] in the more accurate framework of a subsequent paper [Malik G.P., Varma V.S. (2021) JSNM, 34, 1551-1561]. Besides, it distinguishes between the contributions of the electro-electron (e-e) and the hole-hole (h-h) pairs to jc—a feature to which no heed was paid earlier. The essence of our findings is that the jcs of the two samples differ because they are characterized by different values of the primary variables μi and , where is the effective mass of a charge-carrier and me is the free-electron mass and i = 1 and 2 denote Sample 1 and Sample 2, respectively. In the scenario of the charge-carriers being predominantly h-h pairs, the values of these parameters are estimated to be: μ1 ≈ 12.3 meV, η1 ≈ 0.58; μ2 ≈ 22.7 meV, η2 ≈ 0.94. Following from these and similar estimates when the charge-carriers are e-e pairs, given below for each sample are the detailed results for the values of the secondary variables viz. the number density of the charge-carriers and their critical velocity, the number of occupied Landau levels and the magnetic interaction parameter.
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