Taking AuCu3-type sublattice system as an example, three discoveries have been presented: First, the third barrier hindering the progress in metal materials science is that researchers have got used to recognizing exp...Taking AuCu3-type sublattice system as an example, three discoveries have been presented: First, the third barrier hindering the progress in metal materials science is that researchers have got used to recognizing experimental phenomena of alloy phase transitions during extremely slow variation in temperature by equilibrium thinking mode and then taking erroneous knowledge of experimental phenomena as selected information for establishing Gibbs energy function and so-called equilibrium phase diagram. Second, the equilibrium holographic network phase diagrams of AuCu3-type sublattice system may be used to describe systematic correlativity of the composition?temperature-dependent alloy gene arranging structures and complete thermodynamic properties, and to be a standard for studying experimental subequilibrium order-disorder transition. Third, the equilibrium transition of each alloy is a homogeneous single-phase rather than a heterogeneous two-phase, and there exists a single-phase boundary curve without two-phase region of the ordered and disordered phases; the composition and temperature of the top point on the phase-boundary curve are far away from the ones of the critical point of the AuCu3 compound.展开更多
Taking Au3Cu-type sublattice system as an example, three discoveries have been presented. First, the fourth barrier to hinder the progress of metal materials science is that today’s researchers do not understand that...Taking Au3Cu-type sublattice system as an example, three discoveries have been presented. First, the fourth barrier to hinder the progress of metal materials science is that today’s researchers do not understand that the Gibbs energy function of an alloy phase should be derived from Gibbs energy partition function constructed of alloy gene sequence and their Gibbs energy sequence. Second, the six rules for establishing alloy gene Gibbs energy partition function have been discovered, and it has been specially proved that the probabilities of structure units occupied at the Gibbs energy levels in the degeneracy factor for calculating configuration entropy should be degenerated as ones of component atoms occupied at the lattice points. Third, the main characteristics unexpected by today’s researchers are as follows. There exists a single-phase boundary curve without two-phase region coexisting by the ordered and disordered phases. The composition and temperature of the top point on the phase-boundary curve are far away from those of the critical point of the Au3Cu compound; At 0 K, the composition of the lowest point on the composition-dependent Gibbs energy curve is notably deviated from that of the Au3Cu compounds. The theoretical limit composition range of long range ordered Au3Cu-type alloys is determined by the first jumping order degree.展开更多
An approximate calculation of the exchange interaction constant J_(RT)between the rare-earth sublattice and the transition metal sublattice in R_2Fe_(17-x)Al_x (R= Tb,Gd, and Dy) compounds is given by the molecular-fi...An approximate calculation of the exchange interaction constant J_(RT)between the rare-earth sublattice and the transition metal sublattice in R_2Fe_(17-x)Al_x (R= Tb,Gd, and Dy) compounds is given by the molecular-field model and the results of neutron diffraction.The calculated values, -J_(R,T)/k, for Dy_2Fe_(17-x)Al_x (x=5, 6, 7 and 8), Tb_2Fe_(10)Al_7,Gd_2Fe_(17-x)Al_x (x=7, 8) compounds are 8.62K, 8.64K, 9.52K, 10.34K and 10.66K, 10.65K, and 9.85K,respectively, they are in agreement with the experimental values, -J_(R,T)/k, of Dy_2Fe_(17-x)Al_x(x=5, 6, 7 and 8), Tb_2Fe_(10)Al_7 and Gd_2Fe_(17-x)Al_x (x=7, 8) compounds, which are 8.77K, 9.25K,10.1K, 10.9K and 10.35K, 10.1K, and 10.3K, respectively. The origins of the difference between thecalculated and the experimental results are discussed.展开更多
Magnetizations of four sublattice bilayer system have been systematically investigated by the use of effectivefield theory with self-spin correlations and differential operator technique. The effects of the crystal fi...Magnetizations of four sublattice bilayer system have been systematically investigated by the use of effectivefield theory with self-spin correlations and differential operator technique. The effects of the crystal field, longitudinal magnetic field, and intra- and inter-monolayer interaction constants on magnetizations axe examined in detail. Some interesting results are obtained, which may potentially be related to experimental work.展开更多
We present a theoretical study of quantum charge pumping in metallic armchair graphene nanoribbons using the Floquet Green function method. A central part of the ribbon acting as the scattering region is supposed to h...We present a theoretical study of quantum charge pumping in metallic armchair graphene nanoribbons using the Floquet Green function method. A central part of the ribbon acting as the scattering region is supposed to have staggered sublattiee potential to open a finite band gap. A single ae gate is asymmetrically applied to a part of the scattering region to drive the pumping. Corresponding to the gap edges, there are two pumped current peaks with opposite current directions, which can be reversed by changing the position of the ac gate relative to the scattering region. The effects of the parameters, such as the staggered sublattice potential, the driving frequency and the geometric parameters of the structure, on the pumping are discussed.展开更多
We investigate the chiral edge states-induced Josephson current–phase relation in a graphene-based Josephson junction modulated by the off-resonant circularly polarized light and the staggered sublattice potential.By...We investigate the chiral edge states-induced Josephson current–phase relation in a graphene-based Josephson junction modulated by the off-resonant circularly polarized light and the staggered sublattice potential.By solving the Bogoliubov–de Gennes equation,a φ_(0) Josephson junction is induced in the coaction of the off-resonant circularly polarized light and the staggered sublattice potential,which arises from the fact that the center of-mass wave vector of Cooper pair becomes finite and the opposite center of-mass wave vector to compensate is lacking in the nonsuperconducting region.Interestingly,when the direction of polarization of light is changed,-φ_(0) to φ_(0) transition generates,which generalizes the concept of traditional 0–πtransition.Our findings provide a purely optical way to manipulate a phase-controllable Josephson device and guidelines for future experiments to confirm the presence of graphene-based φ_(0)Josephson junction.展开更多
基金Project(51071181)supported by the National Natural Science Foundation of ChinaProject(2013FJ4043)supported by the Natural Science Foundation of Hunan Province,China
文摘Taking AuCu3-type sublattice system as an example, three discoveries have been presented: First, the third barrier hindering the progress in metal materials science is that researchers have got used to recognizing experimental phenomena of alloy phase transitions during extremely slow variation in temperature by equilibrium thinking mode and then taking erroneous knowledge of experimental phenomena as selected information for establishing Gibbs energy function and so-called equilibrium phase diagram. Second, the equilibrium holographic network phase diagrams of AuCu3-type sublattice system may be used to describe systematic correlativity of the composition?temperature-dependent alloy gene arranging structures and complete thermodynamic properties, and to be a standard for studying experimental subequilibrium order-disorder transition. Third, the equilibrium transition of each alloy is a homogeneous single-phase rather than a heterogeneous two-phase, and there exists a single-phase boundary curve without two-phase region of the ordered and disordered phases; the composition and temperature of the top point on the phase-boundary curve are far away from the ones of the critical point of the AuCu3 compound.
基金Project(51071181)supported by the National Natural Science Foundation of ChinaProject(2013FJ4043)supported by the Natural Science Foundation of Hunan Province,China
文摘Taking Au3Cu-type sublattice system as an example, three discoveries have been presented. First, the fourth barrier to hinder the progress of metal materials science is that today’s researchers do not understand that the Gibbs energy function of an alloy phase should be derived from Gibbs energy partition function constructed of alloy gene sequence and their Gibbs energy sequence. Second, the six rules for establishing alloy gene Gibbs energy partition function have been discovered, and it has been specially proved that the probabilities of structure units occupied at the Gibbs energy levels in the degeneracy factor for calculating configuration entropy should be degenerated as ones of component atoms occupied at the lattice points. Third, the main characteristics unexpected by today’s researchers are as follows. There exists a single-phase boundary curve without two-phase region coexisting by the ordered and disordered phases. The composition and temperature of the top point on the phase-boundary curve are far away from those of the critical point of the Au3Cu compound; At 0 K, the composition of the lowest point on the composition-dependent Gibbs energy curve is notably deviated from that of the Au3Cu compounds. The theoretical limit composition range of long range ordered Au3Cu-type alloys is determined by the first jumping order degree.
基金This work was supported by the Research Fund of Hebei Education Committee(Grant No.2001108).
文摘An approximate calculation of the exchange interaction constant J_(RT)between the rare-earth sublattice and the transition metal sublattice in R_2Fe_(17-x)Al_x (R= Tb,Gd, and Dy) compounds is given by the molecular-field model and the results of neutron diffraction.The calculated values, -J_(R,T)/k, for Dy_2Fe_(17-x)Al_x (x=5, 6, 7 and 8), Tb_2Fe_(10)Al_7,Gd_2Fe_(17-x)Al_x (x=7, 8) compounds are 8.62K, 8.64K, 9.52K, 10.34K and 10.66K, 10.65K, and 9.85K,respectively, they are in agreement with the experimental values, -J_(R,T)/k, of Dy_2Fe_(17-x)Al_x(x=5, 6, 7 and 8), Tb_2Fe_(10)Al_7 and Gd_2Fe_(17-x)Al_x (x=7, 8) compounds, which are 8.77K, 9.25K,10.1K, 10.9K and 10.35K, 10.1K, and 10.3K, respectively. The origins of the difference between thecalculated and the experimental results are discussed.
基金The project supported by the Natural Science Foundation of Liaoning Province under Grant No.20041021the Scientific Foundation of the Educational Department of Liaoning Province under Grant Nos.2004C006 and 20060638the Postdoctoral Foundation of Shenyang University of Technology
文摘Magnetizations of four sublattice bilayer system have been systematically investigated by the use of effectivefield theory with self-spin correlations and differential operator technique. The effects of the crystal field, longitudinal magnetic field, and intra- and inter-monolayer interaction constants on magnetizations axe examined in detail. Some interesting results are obtained, which may potentially be related to experimental work.
基金Supported by the K.C.Wong Magna Fund in Ningbo Universitythe National Natural Science Foundation of China under Grant No 11474174
文摘We present a theoretical study of quantum charge pumping in metallic armchair graphene nanoribbons using the Floquet Green function method. A central part of the ribbon acting as the scattering region is supposed to have staggered sublattiee potential to open a finite band gap. A single ae gate is asymmetrically applied to a part of the scattering region to drive the pumping. Corresponding to the gap edges, there are two pumped current peaks with opposite current directions, which can be reversed by changing the position of the ac gate relative to the scattering region. The effects of the parameters, such as the staggered sublattice potential, the driving frequency and the geometric parameters of the structure, on the pumping are discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12104232,11805103,and 11804167)the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20190137 and BK20180739)+2 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.020414380195 and B230201042)the Jit-b Project(Grant No.201831)the Natural Science Fund of Nanjing University of Posts and Telecommunications(Grant No.NY222163)。
文摘We investigate the chiral edge states-induced Josephson current–phase relation in a graphene-based Josephson junction modulated by the off-resonant circularly polarized light and the staggered sublattice potential.By solving the Bogoliubov–de Gennes equation,a φ_(0) Josephson junction is induced in the coaction of the off-resonant circularly polarized light and the staggered sublattice potential,which arises from the fact that the center of-mass wave vector of Cooper pair becomes finite and the opposite center of-mass wave vector to compensate is lacking in the nonsuperconducting region.Interestingly,when the direction of polarization of light is changed,-φ_(0) to φ_(0) transition generates,which generalizes the concept of traditional 0–πtransition.Our findings provide a purely optical way to manipulate a phase-controllable Josephson device and guidelines for future experiments to confirm the presence of graphene-based φ_(0)Josephson junction.
