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Masaru Sugiyama, Naoki Kaneyama, Kouji Mizuno
Subject area: Statistical physics and thermodynamics.
1995 Volume 64 Issue 1 Pages
1-4
Published: January 01, 1995
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Reflection of nonlinear waves, which are excited by impulsive forces, in one-dimensional crystal lattices at finite temperatures, and dynamic fracture of the lattice induced by the reflection are numerically analyzed using the basic statistical-mechanical equations proposed in the preceding paper. Enhancement of the strength of the reflected waves, and typical fracture patterns are found. Their physical implications are also briefly discussed. The equations are, therefore, confirmed to be valid for analyzing such nonequilibrium phenomena.
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Setsuo Yoshida, Yuhji Tsujimi, Toshirou Yagi
Subject area: Equations of state, phase equilibria, and phase transitions.
1995 Volume 64 Issue 1 Pages
5-8
Published: January 01, 1995
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The longitudinal acoustic mode propagating along the three-fold z axis in NaNO
3 has been studied by Brillouin scattering in the temperature range between 23.22°C and 299.55°C.The frequency shift and the spectral width of the Brillouin peakshow anomalous behavior near the transitiontemperature T
c=276.5°C.The relaxation time of the antiferrodistortive mode of NO
3 ionsis calculated from these anomalies through the use ofDebye type susceptibility.The temperature dependence of the relaxationtime has been determined below T
c to be τ
f/(T
c-T)whereτ
fis(6.0 ± 0.7)× 10
-1sec· deg.
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Kenji Shiraishi, Yukio Saito
Subject area: Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties).
1995 Volume 64 Issue 1 Pages
9-13
Published: January 01, 1995
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The Kuramoto-Sivashinsky (KS) equation describes the step front evolution with the diffusional instability. By including the crystalline anisotropy ε in the KS equation, the dynamical morphology transition from the spatio-temporal chaos (STC) to the periodic (P) front is observed by increasing ε . The front velocity is independent of ε for the STC phase, whereas it is inversely proportional to ε for the P phase. At the transition the velocity is continuous.
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Yoshimasa Isawa
Subject area: Electronic transport in condensed matter.
1995 Volume 64 Issue 1 Pages
14-18
Published: January 01, 1995
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We report how the conductance oscillations are varied when there are potential fluctuations in the semiconductor quantum dot. We find that the potential fluctuations lead to an irregular and a nonmonotonic change of the peak heights as a function of the gate voltage and each one increases or decreases as a function of temperature from peak to peak. The details are sensitive to the change of the randomness in the potential. We show that these anomalous features, although they differ from device to device, are observed universally when the fabrication is not complete.
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Akinobu Kanda, Shun–ichi Kobayashi
Subject area: Electronic transport in condensed matter.
1995 Volume 64 Issue 1 Pages
19-21
Published: January 01, 1995
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We have measured the temperature dependence of zero-bias resistance R(T) of a two-dimensional array of small tunnel junctions with normal-statetunneling resistance of R
N=32kΩ.Both in normal and superconducting states, R(T) showedsquare-root-cusp-type behavior, typical of the chargeKosterlitz-Thouless-Berezinskii (KTB) transition, in limited temperature ranges. The transition temperature in the superconducting state, estimated from R(T), is about four times larger than that in the normal state.We consider these features to beevidence of precursor effects of the charge KTB transition.
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Hiroyuki Deguchi, Seishi Takagi, Masakazu Ito, Kazuyoshi Takeda
Subject area: Magnetic properties and materials.
1995 Volume 64 Issue 1 Pages
22-25
Published: January 01, 1995
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Electron spin resonance (ESR) and magnetization measurements have been performed on the diluted Haldane system (CH
3)
4NNi
1-xZn
x(NO
2)
3 (Zn
2+:TMNIN). We observed ESR absorption from the S=1/2 moment at the end of the Ni
2+ chains at low temperatures. The dependence of the ESR absorption intensity on temperature and the concentration of Zn
2+ are compared to the theory derived from the valence bond solid (VBS) model by Mitra, Halperin and Affleck (Phys. Rev. B 45 (1992) 5299). The paramagnetic contribution to the magnetization of Zn
2+:TMNIN increases with Zn
2+ concentration. We find that on average, one S=1/2 moment appears on each segment of finite chains at low temperatures.
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Hikaru Kawamura
Subject area: Magnetic properties and materials.
1995 Volume 64 Issue 1 Pages
26-30
Published: January 01, 1995
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Chiral-glass ordering of the nearest-neighbor Heisenberg spi glass in three dimensions is studied through Monte Carlo simulations. Sharp growth of chiral correlations is observed at low temperatures. The data are consistent with the occurrence of a finite-temperature chiral-glass transition lying in the universality class of the three-dimensional Ising spin glass, while the possibility of a T=0 chiral-glass transition with an exponential (or nearly exponential) divergence cannot be ruled out.
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Takashi Nagatani
Subject area: Other areas of research of general interest to physicists.
1995 Volume 64 Issue 1 Pages
31-34
Published: January 01, 1995
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The deterministic cellular automaton 184 (the one-dimensional asymmetric simple-exclusion model with parallel dynamics) is extended to take into account injection or extraction of particles. The model presents the traffic flow on a highway with inflow or outflow of cars. Introducing injection or extraction of particles into the asymmetric simple-exclusion model drives the system asymptotically into a steady state exhibiting a self-organized criticality. The typical lifetime
of traffic jams scales as ≅ Lν with ν =0.65± 0.04. It is shown that the cumulative distribution Nm (L) of lifetimes satisfies the finite-size scaling form Nm (L) ≅ L-1 f(m/Lν).
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Satoshi Yukawa, Macoto Kikuchi
Subject area: Other areas of research of general interest to physicists.
1995 Volume 64 Issue 1 Pages
35-38
Published: January 01, 1995
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We propose a new model of one-dimensional traffic flow using a coupled map lattice. In the model, each vehicle is assigned a map and changes its velocity according to it. A single map is designed so as to represent the motion of a vehicle properly, and the maps are coupled to each other through the headway distance. By simulating the model, we obtain a plot of the flow against the concentration similar to the observed data in real traffic flows. Realistic traffic jam regions are observed in space-time trajectories.
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Hideaki Ujino, Miki Wadati
Subject area: Mathematical methods in physics.
1995 Volume 64 Issue 1 Pages
39-56
Published: January 01, 1995
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Infinite algebra, which we call \widehat{su(ν )}-W
∞ algebra, is constructed from the Lax operator of the SU(ν ) quantum Calogero model. The generalized Lax equations for the W-operators are explicitly shown. An algebraic construction of the eigenstates of the model is demonstrated.
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Masahiro Shiroishi, Miki Wadati
Subject area: Mathematical methods in physics.
1995 Volume 64 Issue 1 Pages
57-63
Published: January 01, 1995
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Following Korepanov's idea of the tetrahedral Zamolodchikov algebra, we prove the Yang-Baxter equation for the R-matrix related to the 1D Hubbard model. Based on the result, we present generalizations of the Shastry's bilayer vertex model.
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Shintaro Mori, Kenichi Kawanishi, Miki Wadati
Subject area: Statistical physics and thermodynamics.
1995 Volume 64 Issue 1 Pages
64-67
Published: January 01, 1995
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We present a statistical mechanics of D-dimensional self-avoiding tethered membranes with disorders in d-dimensional space. Using the variational method, we investigate the properties of dilute and semi-dilute solutions. With an assumption of the replica symmetry, we obtain the saddle point equations which contain the screening effects. In the semi-dilute density the renormalized interaction is characterized by the screening length. The crumpled and the crumpled glass phases are considered. For d<4 and semi-dilute case, the membranes are more crumpled than the membranes with no disorder. The phase diagrams of the crumpled and crumpled glass phases in (d, D) planes are obtained for both densities. Using a scaling argument, we find the density dependencies of physical quantities, such as radius of gyration, screening length and osmotic pressure.
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Tomoyuki Nagaya, Hiroshi Orihara, Yoshihiro Ishibashi
Subject area: Statistical physics and thermodynamics.
1995 Volume 64 Issue 1 Pages
78-85
Published: January 01, 1995
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Dynamics of interacting +1 and -1 disclinations in the two-dimensionally aligned nematics was investigated experimentally. A position and a sign of individual disclination were measured from the image of polarizing microscope, and then the spatial distribution of disclinations was analyzed by calculating the correlation functions of the number density of disclinations and the distribution functions of the separation of kth-nearest-neighbor disclination pairs. As a result of the interaction among the disclinations, the distribution of disclinations deviates from the random distribution. Each disclination is influenced strongly by other disclinations existing within a distance less than several times of the nearest-neighbor distance. In addition, the correlation functions of the number density of disclinations obtained in the experiment can be well described by the theory for the vortices in the two-dimensional XY system [F. Liu and G. F. Mazenko: Phys Rev. B 46 (1992) 5963].
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Kiyomi Okamoto, Yohtaro Ueno
Subject area: Statistical physics and thermodynamics.
1995 Volume 64 Issue 1 Pages
86-92
Published: January 01, 1995
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We present a quantum version of the twist method which has been developed for classical systems. A finite size scaling form for the excess ground state energy is derived and tested for an S=1/2 antiferromagnetic Heisenberg chain with next nearest neighbor interactions: H= J ∑ (S
j · S
j+1 +α S
j · S
j+2 )with J>0 and α >0. Using an exact diagonalization method, we obtain the critical value α
c ≅ 0.246 of the fluid-dimer transition, which is very close to the reliable value recently obtained by Okamoto and Nomura (Phys. Lett. A 169 (1992) 433).
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Fumiaki Shibata, Mari Yasufuku, Chikako Uchiyama
Subject area: Statistical physics and thermodynamics.
1995 Volume 64 Issue 1 Pages
93-98
Published: January 01, 1995
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A mathematical correspondence is established between a set of equations due to Mori formalism and those of generalized tri-diagonal recurrence relations. Thus, once a set of coupled equations describing physical phenomena are given, the corresponding Langevin equations can be obtained directly. This enables us to construct a hierarchical structure of physical variables and time scales
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Hiroshi Orihara, Yoshihiro Ishibashi
Subject area: Statistical physics and thermodynamics.
1995 Volume 64 Issue 1 Pages
99-105
Published: January 01, 1995
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The nonlinear after-effect functions and susceptibilities for uniaxial ferroelectrics and ferroelectric liquid crystals are derived on the basis of equations of motion. The ferroelectrics and the ferroelectric liquid crystals are quite different in the functional forms of nonlinear after-effect functions and the nonlinear susceptibilities, though they are the same in those of the linear ones. On the basis of the results the validity of so-called Nakada's formula, which has been often used in analyzing experimental data, is also discussed.
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Kenshi Nakamura, Tohru Nakano
Subject area: Fluid dynamics.
1995 Volume 64 Issue 1 Pages
106-113
Published: January 01, 1995
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We investigate the global and local structure of the enstrophy dissipation rate in two-dimensional turbulence simulated on 512
2 mesh points from a multifractal point of view. The generalized dimensions D
q could be determined for any positive value of q. D
q for q≤ q
0 (-- 4) reflect a global nature of the dissipative structure and may be universal. On the other hand, D
q for q>> q
0 put the emphasis on the local structure and they may not be universal. We confirm that the scaling holds on smaller squares chosen arbitrarily. Dividing the system into 64 squares of size of 64 mesh points, we obtain the distribution of D
q; it has a broad spectrum. Finally, the most intense region is found to consist of many layers of positive and negative vorticity.
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Yushi Kato, Shigeyuki Ishii
Subject area: The physics of plasmas and electric discharges.
1995 Volume 64 Issue 1 Pages
114-123
Published: January 01, 1995
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Fundamental processes of the ECR (electron cyclotron resonance) multiply charged ion source have been experimentally studied with a two-stage mirror field configuration. A model based on cumulative ionization processes has been proposed to investigate charge-state distributions (C.S.D.) of argon ions. Experimental results and simulations have suggested that high temperature electrons are essentially important for multicharged-ion production. Multiple-ionization processes are additionally introduced to this modelling and quantitatively assessed by using up-to-date cross section data. It is concluded that the multiple ionization has only a small effect on the C.S.D. in the low electron temperature, but a significant effect for the case including high energy component.
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Ramireddygari V. Reddy, Kunihiko Watanabe, Tomohiko Watanabe, Tetsuya ...
Subject area: The physics of plasmas and electric discharges.
1995 Volume 64 Issue 1 Pages
124-135
Published: January 01, 1995
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Basic properties of an impulsive Alfven interaction between the fully-ionized bulk plasma and the weakly-ionized boundary plasma, e.g., between the magnetosphere and the ionosphere, have been studied by means of a three-dimensional self-consistent simulation of the coupled plasma system. It is found that the duration time of an impulsive perturbation given in the fully-ionized bulk plasma, the spatial distribution of the Alfven propagation time, and the ratio between the impedance of the fully-ionized plasma and the resistance of the weakly-ionized plasma are the key factors that determine the propagation dynamics and the weakly-ionized plasma responses for an impulsive MHD perturbation.
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Eiichi Tanaka, Sayaka Ishibashi, Kohji Abe, Masaru Suzuki, Takeshi Shi ...
Subject area: Mechanical and acoustical properties of condesed matter.
1995 Volume 64 Issue 1 Pages
136-141
Published: January 01, 1995
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Ultrasonic and Brillouin scattering measurements were performed near the incommensurate (INC) transition of SiO
2 (quartz). The decrease of the LA sound velocity in the INC phase was found to be much less for 10 MHz than for 27 GHz, being remarkably different from other crystals which undergo INC phase transitions. The dispersion in the INC phase can be well characterized by a simple Landau-Khalatnikov type relaxation with a relaxation time τ (T)= (2.6 ± 0.5 )× 10
-12 (T
i- T)
-1s.A small but critical decrease of the TA velocity as T → T
c (=T
i -1.4 K) was also detected by the ultrasonic measurement.
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H. C. Gupta, Balram
Subject area: Lattice dynamics and crystal statistics.
1995 Volume 64 Issue 1 Pages
142-145
Published: January 01, 1995
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Lattice dynamical calculations of inverse spinel type sulphides AB
2X
4 have been performed using a force constant model. The dynamical matrix for the first time has been analytically solved at the zone centre. The analytical solution provides 5 Raman modes similar to the normal spinel structure and 24 infrared modes different from the normal spinel compounds. It has been found that the randomness of the A- and B-ions on the octahedral sites does not change the frequencies theoretically in the present treatment where the interatomic interactions are confined upto third nearest neighbour. Similar to normal spinel sulphides, it has been found that the nearest neighbour interatomic interaction (tetrahedral) is weaker than next nearest interaction (octahedral). The agreement obtained between theory and the available experimental results in case of MnIn
2S
4, FeIn
2S
4, CoIn
2S
4 and NiIn
2S
4 is satisfactory.
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Keisuke Tanaka, Tomohiro Shimada, Yasuo Nishihata, Akikatsu Sawada
Subject area: Equations of state, phase equilibria, and phase transitions.
1995 Volume 64 Issue 1 Pages
146-154
Published: January 01, 1995
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In order to clarify the roles of cation and anion molecules in the ferridistortivephase transition, four kinds of single crystals of [A(CH
3)
4+]
2XBr
42- type, where cat-ion sites are occupied either by tetramethylphosphonium ion P(CH
3)
4+ or by tetramethylammonium ion N(CH
3)
4+, and anion site either by tetrabromocobaltate ion CoBr
42- or by tetrabromomanganate ion MnBr
42-, have been grown. The temperature dependence of the spontaneous shear strain x
5s(T)=(π / 180°)(β (T)-90°), where β (T) is the monoclinic angle, has been measured from 420 K down to 20 K. The substitution for cations is found to cause a major change in the temperature dependence of x
5s(T), while the substitution for anion only a minor one. The results are explained on the basis of a ferridistortive model whose spontaneous strain consists of two kinds of sublattice strains. It is concluded that cations A(CH
3)
4+ play a primary role in the ferridistortive phase transition in [A(CH
3)
4+]
2XBr
42- type crystals, while anion XBr
42- a secondary one.
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Yoshihiro Ishibashi, Makoto Iwata
Subject area: Equations of state, phase equilibria, and phase transitions.
1995 Volume 64 Issue 1 Pages
155-158
Published: January 01, 1995
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A Landau free energy proposed for the phase transitions in phospholipid bilayers has been reexamined, and the phase diagram in the adopted parameter space is presented. The temperature dependences of specific heat and the elastic stiffness constant associated with the order parameter derived from the given free energy function are shown.
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Yoshimi Tsuchiya
Subject area: Thermal properties of condensed matter.
1995 Volume 64 Issue 1 Pages
159-163
Published: January 01, 1995
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The specific heat, molar volume, and sound velocity have been measured to investigate the thermodynamics of structural changes in liquid CdSb, from which the volume expansion coefficient and isothermal compressibility have also been deduced. These thermodynamic functions show unusually large temperature dependence around the melting point. It is shown that the Ehrenfest's relations in an extended form are satisfied, which gives strong support to chemical clusters in the liquid CdSb which dissociates with raising temperature.
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Michiaki Matsukawa, Fumiaki Tatezaki, Hiromitsu Ogasawara, Koshichi No ...
Subject area: Thermal properties of condensed matter.
1995 Volume 64 Issue 1 Pages
164-169
Published: January 01, 1995
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The thermal conductivity of the Ag-BPSCCO composite system is studied in the temperature range from 15 K to 200 K. The percolation threshold value of Ag (f
c) is estimated to be 0.25, which is rather close to the three-dimensional percolation threshold (0.16). The observed values of critical exponents near the percolation threshold, t'(f>f
c) and s'(f
c), are 1.08 and 0.63, respectively. The observed value of t' is not consistent with the universal value (t=2) in the metal-insulator mixture. This discrepancy is discussed within the framework of the scaling theory. In the first order approximation, the critical behavior below fc in the Ag-BPSCCO composite is determined by that in the superconductor-normal conductor composite. The thermal conductivity above fc is explained by the critical property of the good conductor-bad conductor composite with the finite conductivity ratio.
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Masanobu Kusakabe, Yoshiyuki Shirakawa, Shigeru Tamaki, Yoshio Ito
Subject area: Transport properties of condensed matter (nonelectronic).
1995 Volume 64 Issue 1 Pages
170-176
Published: January 01, 1995
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Total electrical conductivities and transferencenumbers of the Ag
xCu
1-xI in α-phase have beenmeasured as a function of temperature and composition.In this phase, it has been recognized that both Ag
+ and Cu
+ could be mobile accompanying with that the activation energiesfor both mobile ions are nearly the same and the transferencenumber of both ions deviate from ideal values.This result indicates that the both mobile ions have the sameconducting path although the amplitudes of their anharmonic thermal vibrations are different.
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Kazumoto Iguchi
Subject area: Electron states in condensed matter.
1995 Volume 64 Issue 1 Pages
177-184
Published: January 01, 1995
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The electronic spectrum of one-dimensional quasiperiodic materialssuch as AB
1-xC
x (0≤ x≤ 1) is calculated hereinwithin the framework of the off-diagonal tight-binding model by using asimple scheme of the theory of the binary quasiperiodic lattices.The spectrum shows a Cantor-set of energy bands and consists of a centerband gap for the whole range of x.We find that unless the potential difference is too strong, the magnitude of the center band gap Δ
x is interpolated by aVegard's law type linear relation with respect to x asΔ
x=(1-x)Δ
ab+xΔ
ac, where Δ
ab (Δ
ac)is the band gap for the regular AB (AC) alloy.This means that this system is a semiconductor for0≤ x≤ 1.We also show that the center gap follows the Saxon-Hutner-Luttinger theorem.
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Shinpei Fujii, Shoji Ishida, Setsuro Asano
Subject area: Electron states in condensed matter.
1995 Volume 64 Issue 1 Pages
185-191
Published: January 01, 1995
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Band calculation results show that Heusler compounds Fe
2MnZ (Z=Al, Si, P) have a band gap near the Fermi energy for one spin direction. Except for Fe
2MnSi, the compounds does not have a half-metallic character because there is a slight density of states at the Fermi energy in the minority-spin state. An analysis of density of states indicates that there exists sufficiently strong d-d hybridization between metal atoms and weak p-d hybridization between Si and metal atoms. Due to this weakness, the replacement of Si by Al or P does not cause considerable change in the DOS structure. However, the weak hybridization defines the electronic character of the system.
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Kouichi Jouda, Satoshi Tanaka, Kazuo Soda, Osamu Aita
Subject area: Electron states in condensed matter.
1995 Volume 64 Issue 1 Pages
192-199
Published: January 01, 1995
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X-ray emission spectra (XES) due to the 5p→ 3d electronic transition in LaF
3, La
2O
3 and CeF
3 are investigated by the X-ray excitation and the electron bombardment. Strong variation in the shape of XES in these compounds is observed in the X-ray excitation. It is shown by a theoretical analysis that this variation is mainly due to the difference of the hybridization effect in the excited state with a 3d core hole. In the electron bombardment, the spectral features are not so much changed among these compounds as in the X-ray excitation, because the 3d4f
n+1 configuration created by the 3d→ 4f direct excitation hardly hybridizes with the 3d4 f
n+2\underline{L} configuration.
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Shin–ichi Kimura, Yasuhiko Sato, Takashi Suzuki, Mikihiko Ikezaw ...
Subject area: Electron states in condensed matter.
1995 Volume 64 Issue 1 Pages
200-209
Published: January 01, 1995
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Reflectivity spectra of a magnetic semiconductor Gd
2S
3 (=Gd
3-x\Box
xS
4, where \Box denotes vacancy and x≅ 1/3) have been measured in the photon energy range from 2 meV to 0.5 eV at 14 K under magnetic field up to 5 tesla. The energy gap of about 7 meV at 0 tesla was observed to become narrow as the magnetic field increases and to collapse at 3.3 tesla. The origin of the energy gap is attributed to the trapped magnetic polaron. Another absorption band around 0.1 eV of which origin has been unclear is concluded to be the deep state of the magnetic polaron because it was shifted by the magnetic field.
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Yoshihiko Hirano, Toshimitsu Fujita, Kazushige Machida, Tetsuo Ohmi
Subject area: Superconductivity.
1995 Volume 64 Issue 1 Pages
210-221
Published: January 01, 1995
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By numerically analyzing the canonical Ginzburg-Landau (GL) free energy functional with two component order parameters under magnetic fields (H), it is shown that the observed phase diagrams in UPt
3 for both orientations of H⊥ c and H//c in D
6h can be explained consistently. The mysterious field dependence of the unit cell angle of the vortex lattices observed by the neutron scattering experiment is quantitatively reproduced. The predicted diamagnetic term in the above GL turns out to be indispensable to understand these facts. This unambiguously demonstrates that the non-trivial vortex lattices are formed in each domain of temperature and field, reflecting the underlying unconventional pairing symmetry in UPt
3, and strengthening the validity of the canonical GL functional form which is independent of detailed pairing mechanism. Based on the present calculations possible orientational-dependent phase diagrams under pressures are predicted.
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Yutaka Itoh
Subject area: Superconductivity.
1995 Volume 64 Issue 1 Pages
222-231
Published: January 01, 1995
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The wave-number dependent BCS spin susceptibility χ (q) with various-type anisotropic superconducting gap parameters Δ (q) is calculated for a two dimensional nearly antiferromagnetic Fermi liquid model with the random-phase-approximation (RPA). The Δ (q) anisotropic but gapful on the Fermi surface gives rise to a significant reduction of χ (q) around q=Q[=(π, π)]. The enhanced χ (q-- Q) below T
c as large as above T
c can be traced to the d(x
2-y
2)-wave gap parameter or the nodeless anisotropic gap parameter with the specific minimum gap, Δ
min (0.35<2 Δ
min/k
BT
c<0.7), on the Fermi surface. From the experimental findings on the enhanced χ (q-- Q) below T
c and the anisotropic Δ (q) on the Fermi surface for the high-T
c Cu oxides, we conclude that the d(x
2-y
2)-wave gap parameter is realized but not the other types in the high-T
c superconductivity, except the additional change of the order parameter.
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Tomomi Kurata, Hikaru Kawamura
Subject area: Magnetic properties and materials.
1995 Volume 64 Issue 1 Pages
232-241
Published: January 01, 1995
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Phase transitions of the frustrated Ising model on a stacked-triangular lattice with the antiferromagnetic nearest-neighbor and the ferromagnetic next-nearest-neighbor interactions are studied. For this system, an earlier mean-field analysis yielded successive phase transitions, with a partial disordered phase stabilized in an intermediate temperature range and ferrimagnetic phases stabilized at lower temperatures. We have performed an extended mean-field analysis based on the variational principle in which correlation effects in the frustrated triangular layer are taken into account. It is found that the partial disordered phase is largely suppressed relative to the ferrimagnetic phase due to the correlation effects.
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Yuuichi Tazuke, Shin–ichi Shibata, Keiko Nakamura, Hisamasa Yano
Subject area: Magnetic properties and materials.
1995 Volume 64 Issue 1 Pages
242-250
Published: January 01, 1995
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A trial is made for determining the origin of exchangeinteractions between spins of two intercalation compounds, Fe
0.05TiS
2 and Co
0.1TiS
2, by comparing the change in spin glass transition temperature T
gaccompanying a change in conduction electron number.For the purpose of changing the conduction electron number, 5\are substituted by Ta.In Co
0.1TiS
2, T
g changes and the RKKY interaction may bethe dominant exchange interaction.In Fe
0.05TiS
2, although the change in T
g is small, a tendency toward the RKKY interaction is suggested.
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Tôru Sakai
Subject area: Magnetic properties and materials.
1995 Volume 64 Issue 1 Pages
251-259
Published: January 01, 1995
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The S=1/2 bond alternating Heisenberg spin chain in a magnetic field is studied by the numerical diagonalization and the finite size scaling based on the conformal field theory. It is found that the magnetic state (0
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