-
Masuo Suzuki
1988 Volume 57 Issue 1 Pages
1-4
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
A new method is proposed to estimate critical exponents by applying the CAM theory to continued-fraction expansions of static and dynamic response functions. Some mathematical and physical examples are studied utilizing this new method to demonstrate its usefulness.
View full abstract
-
Toshimi Suda, Osamu Konno, Izumi Nomura, Toshiji Suzuki, Tatsuo Terasa ...
1988 Volume 57 Issue 1 Pages
5-8
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
Measurements of the cross sections of
10B(γ, p) and
10B(γ, pn) with tagged photons have been performed at
Eγ=66∼103 MeV. The results of both the
10B(γ, p) and (γ, pn) measurement show the dominance of a two-nucleon photoabsorption process in this energy region.
View full abstract
-
Kunihito Nagayama
1988 Volume 57 Issue 1 Pages
9-12
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
An exact and analytical solution of the Riemann problem for solids has been obtained. It is assumed that the square of the acoustic impedance along an isentropic change of state can be expressed as the quadratic function of pressure. A Grüneisen-type equation of state calculated from this assumption has been used and the solution of the Riemann problem obtained after a rather simple calculation. The solution can also be extended to the case of powders, and a numerical example is presented for solid and porous aluminum.
View full abstract
-
Masafumi Sera, Satoru Kunii, Tadao Kasuya
1988 Volume 57 Issue 1 Pages
13-15
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
We have observed the oscillatory magnetostrictions of LaB
6 and PrB
6 single crystals. The de Haas van Alphen frequencies in LaB
6 range from the order of 10
4 to 10
7 gauss and are related to the interconnecting neck orbit between spherical ellipsoids. In PrB
6, only one de Haas van Alphen frequency of 1.4×10
6 gauss is observed. Both results agree well with the conventional de Haas van Alphen measurement but do not agree with the acoustic measurement.
View full abstract
-
Yutaka Okabe, Komajiro Niizeki
1988 Volume 57 Issue 1 Pages
16-19
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
The critical properties of the Ising model on the Penrose lattice of a size up to 439,204 sites are studied by means of the Monte Carlo simulation. We make an analysis of a phenomenological Monte Carlo renormalization group based on finite-size scaling. The critical temperature
Tc and the magnetic critical exponent
yH are obtained to be (2.392±0.004)
J and 1.89±0.02. The value of
yH coincides with the value of a two-dimensional crystal,
yH=1.875, within numerical accuracy.
View full abstract
-
S. G. Chung, Thomas F. George
1988 Volume 57 Issue 1 Pages
20-23
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Based on the generalized Levinson’s theorem, some general properties of quantum sticking coefficients of an atom at 0 K are derived. Good agreement is obtained with experimental results for a
4He atom colliding with a liquid
4He surface.
View full abstract
-
Junji Sakurai, Yoshinori Yamamoto, Yukitomo Komura
1988 Volume 57 Issue 1 Pages
24-25
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The thermoelectric power of MnSi was measured from liquid He temperature to room temperature. The tangential line of thermoelectric power in the high-temperature region above
TN is found not to pass the origin, in disagreement with Mott’s expression. This observation is discussed in connection with the spin fluctuation in the sample, and a new expression of the thermoelectric power taking into account the spin fluctuation is proposed.
View full abstract
-
Kazunori Aoki, Keiichi Yamamoto, Nobumichi Mugibayashi
1988 Volume 57 Issue 1 Pages
26-29
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
The chaotic response of a current filament formed by impact ionization of neutral shallow donors in high-purity
n-GaAs has been investigated at 4.2 K under a dark condition. Stable hysteresis of the S-shaped current-voltage characteristic is perturbed externally by applying ac and dc voltages of the form of
Vo+
Vac sin (2π
fot). Bifurcation routes to chaos are investigated by varying
Vo and
fo simultaneously, in the range of 2 V\lesssim
Vo\lesssim3 V and 0.9 MHz\lesssim
fo\lesssim1.43 MHz, respectively. A period-doubling bifurcation, alternating period-chaotic bifurcation sequence and extrinsic crisis between two limit cycles are observed.
View full abstract
-
Yoshio Kitaoka, Shigeru Hiramatsu, Takayuki Kondo, Kunisuke Asayama
1988 Volume 57 Issue 1 Pages
30-33
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The nuclear relaxation rate 1⁄
T1 and the Knight shift have been studied for both the Cu–O plane and chain sites by Cu nuclear quadrupole (NQR) and magnetic resonance (NMR) techniques. Below
Tc=92 K, 1⁄
T1 for the plane site decreases markedly without the enhancement just below
Tc characteristic for the BCS superconductor, and the Knight shift also shows a more rapid reduction than the BCS prediction, giving evidence of a dominant singlet pairing. In contrast, 1⁄
T1 for the chain site shows a weak temperature dependence below
Tc. This difference of the 1⁄
T1 behavior for the plane and chain Cu sites is attributed to the difference of the relaxation processes, i.e., the magnetic and quadrupole relaxation processes, respectively. From both the behaviors of 1⁄
T1 and the Knight shift at the plane site, it is pointed out that the Cooper pair may be of a d-type formed by a strong coupling with a large energy gap.
View full abstract
-
Takeo Izuyama
1988 Volume 57 Issue 1 Pages
34-37
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
A theoretical model of the Bednorz-Müller system is considered. This is a two-dimensional electron lattice with alternating spin alignment containing a certain number of holes. The isolated holes are fermions with “spin” 1/2. A pair of holes with antiparallel spins falls into a tightly bound state; a charged boson. The condensate of the bosons of this kind forms a superfluid component. An energy gap exists in the excitation spectrum of the isolated holes constituting the normal component. The tightly bound character of the charged boson is reconfirmed by solving exactly the gap equation. The transition temperature is obtained from the condition of the zero gap.
View full abstract
-
Kiichi Amaya, Mamoru Ishizuka, Tadao Nakagawa, Sachihito Saratani, Tos ...
1988 Volume 57 Issue 1 Pages
38-41
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
Magnetizations of the triangular antiferromagnets RbFeCl
3 and RbFeBr
3 are measured in pulsed high magnetic fields up to 40T at liquid
4He temperatures. In the case of RbFeCl
3, the magnetization is found to increase almost linearly from the zero field, and to be flattened at some critical field of 14T. Further application of magnetic fields induces an anomalous double-step magnetization around 31T. The phenomenon is similar to the one which was found in CsFeCl
3 at some higher magnetic field, but noteworthy is the existence of a fine structure in the anomalous magnetization of RbFeCl
3. The anomaly has thus far not been observed for RbFeBr
3 in the measured magnetic fields up to 85T.
View full abstract
-
Masatoshi Imada
1988 Volume 57 Issue 1 Pages
42-45
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
A new hybrid-type algorithm is proposed for simulations of fermion lattices. The direct calculation of the matrix inversion operation is replaced with a stochastic iteration procedure. The computation time grows linearly with the increase of spatial system size. Applications to the Hubbard model on the 6
2, 12
2 and 16
2 square lattices are illustrated with no indication of enhancement for superconducting correlation in the non-half-filled band.
View full abstract
-
Yoshihiro Yamada, Akihiko Sakata
1988 Volume 57 Issue 1 Pages
46-49
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
From Nb NMR and magnetization measurements of the hexagonal C14 Nb
1−yFe
2+y compounds with
y=−0.008∼0.002, the stoichiometric NbFe
2, which was considered to be a paramagnet, has been found to be a weak antiferromagnet with a Néel temperature of about 10 K. The antiferromagnetism is suppressed by external magnetic fields higher than about 6 kOe. Furthermore, the Néel temperature decreases rapidly with deviating the composition from stoichiometry to the Nb-excess side, and at around
y=−0.006 the compound becomes paramagnetic.
View full abstract
-
Katsunori Iio, Hitoshi Hotta, Motoaki Sano, Hiroji Masuda, Hidekazu Ta ...
1988 Volume 57 Issue 1 Pages
50-53
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Birefringence measurement was made on a triangular lattice antiferromagnet CsMnI
3 at temperatures around the Néel point of 11.42 K. The birefringence for light propagating along the hexagonal
c-axis shows that CsMnI
3 has an intermediate ordered phase in the temperature region between 8.20±0.03 K and 11.42 K. Below 8.20 K CsMnI
3 takes the orthorhombic spin structure of the triangular spin arrangement with the spin moments restricted in a plane perpendicular to the basal plane.
View full abstract
-
Mikio Shimizu
1988 Volume 57 Issue 1 Pages
54-56
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
An intensive broadening in line widths of the proton magnetic resonance (PMR) spectrum for the side chain of lysine in a mixture of lysine and UpU (the anticodonic dinucleoside monophosphate of lysine) suggests a specific association between UpU and lysine. The results of NOE (Nuclear Overhauser Effect) experiments also show a large distortion of the side chain of lysine in the pocket of UpU by the lock and key relationship, as indicated by model building. This confirms the validity of the application of the CPK molecular model building technique to the C4N theory on the origin of the genetic code.
View full abstract
-
Tsutomu Kawata
1988 Volume 57 Issue 1 Pages
57-65
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
A new derivation of the completeness relation for Jost functions is directly given by using the Riemann-Hilbert problems. A bilinear functional, depending on
x and
y, is introduced and by using this functional the Gel’fand-Levitan integral equation is represented generally mapping a (ground) state to another (excited) state. We also get a good connection of the Riemann-Hilbert transform (matrices) with the Gel’fand-Levitan equation.
View full abstract
-
Ryogo Hirota
1988 Volume 57 Issue 1 Pages
66-70
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
It is found that the 3+1 dimensional Toda molecule equation in the spherical coordinates
Δ log
Vn=
Vn+1−2
Vn+
Vn−1,
where
Δ=∂
2⁄∂
r2+(2⁄
r)(∂⁄∂
r)+
r−2[∂
2⁄∂θ
2+cot θ(∂⁄∂θ)+(1⁄sin
2 θ)∂
2⁄∂\varphi
2],
which has been introduced by Nakamura, is transformed into the two-dimensional Toda molecule equation under the assumption that
Vn(
r, θ, \varphi)=
r−2Vn(θ, \varphi). General solutions including Nakamura’s are obtained.
View full abstract
-
Takasi Endo
1988 Volume 57 Issue 1 Pages
71-74
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
Quantum theory of phase relaxation (T. Endo: J. Phys. Soc. Jpn
56 (1987) 1684) is applied to reduction process of a wave packet due to measurement. Reduction of a wave packet is a dynamic process derived from interactions between an object quantum system and a measuring apparatus without ensemble averaging.
View full abstract
-
Kazuo Hida
1988 Volume 57 Issue 1 Pages
75-79
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The effect of dissipation on the recovery of the classical chaotic dynamics is discussed in the semiclassical regime of the quantum nonintegrable systems. In the classically chaotic Hamiltonian systems, the semiclassical approach breaks down within rather short time scale due to the interference of the wave function. It is shown that the dissipation suppresses the interference and confines the quantum fluctuation around the semiclassical trajectory which is described by the semiclassical Langevin equation. We also show that the semiclassical condition obtained by Schmid is equivalent to the condition for the suppression of interference. The discussion is valid regardless whether the classical motion is chaotic or not and therefore dissipation helps the recovery of the classical dynamics in the chaotic systems.
View full abstract
-
Hiroshi Hasegawa, Satoshi Adachi
1988 Volume 57 Issue 1 Pages
80-87
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The elliptic cylindrical coordinates of type I adapted to the Fock hypersphere in momentum space of the Kepler motion and their canonical momenta are used to construct an analytic form of the classical action integrals which yield an adequate parametrization of the KAM (Kolmogorov-Arnold-Moser) tori of the Kepler trajectories weakly perturbed by a uniform magnetic field. The semiclassical quantization formula so provided presents a prototype of the exact EBK (Einstein-Brillouin-Kepler) quantization scheme, and the resulting quantized energies vs the magnetic field strength correspond to the quadratic Zeeman spectra of each Rydberg multiplet lifted by the perturbation.
View full abstract
-
Shoso Shingubara, Kiyoshi Hagiwara, Ryo Fukushima, Tatsuyuki Kawakubo
1988 Volume 57 Issue 1 Pages
88-94
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The flow structure and the velocity profile for vortices formed around a sinkhole were examined by means of the dye visualization method and the laser Doppler velocimetry, respectively. A one-celled vortex appeared for small values of the radial Reynolds number
Re and the swirl ratio
S and a two-celled vortex was observed for large values of
Re and
S. The two-celled vortex was found to turn into a turbulent flow with further increases in
Re.
View full abstract
-
Kiyoshi Yatsui
1988 Volume 57 Issue 1 Pages
95-107
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Theoretical and experimental studies are presented on a parametric decay instability into two electrostatic ion cyclotron waves in a two-ion species plasma. Theoretically, by using a hot-electron plasma model, we generalize such a decay instability in the limits of long- and short-wavelength regions. The instability thresholds as well as the growth rates are predicted for these limiting cases. Experimentally, we modulate an electron beam near the sum of the ion cyclotron frequencies in an electron-beam-plasma system to produce an electric field in the radial direction. At high levels of beam modulation above a certain threshold, the beam pumps this instability. Associated ion heating takes place as the instability develops strongly. The instability threshold has been determined in a parameter space. The instability threshold predicted theoretically is compared with that obtained experimentally, and a quantitative agreement is obtained between them.
View full abstract
-
Shobu Kaneko, Hiroaki Tsutsui
1988 Volume 57 Issue 1 Pages
108-116
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The Woltjer-Taylor method is applied to spheromak plasmas in spheroidal flux conservers. As models of the flux conserver, both oblate and prolate spheroidal vessels with a center conductor are used. The plasma is not assumed to be nearly spherical, and the Rayleigh-Ritz method and the finite element method are used to evaluate the eigenvalues. The oblate spheromak is shown to be stable irrespective of the shape of the flux conserver. Though the prolate spheromak is unstable if there is no center conductor, it can be stable if the center conductor is installed.
View full abstract
-
Masatoshi Yagi, Masahiro Wakatani, K. C. Shaing
1988 Volume 57 Issue 1 Pages
117-124
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
When the transport coefficient based on the mixing length theory,
DM, does not include a poloidal mode number,
m, it is exactly the same as the scale invariance result,
DS. For the g mode turbulence in stellarators,
DM and
DS corresponding to the convective and the collisionless stochastic transport coincide with each other. For the rippling mode turbulence in tokamaks,
DM includes
m and disagrees with
DS as well as the collisional stochastic transport in the g mode case. However, by taking account the scale transformation for the poloidal mode number into the expression of
DM, the coincidence is recovered. It is examined how the bootstrap current produced by the electrostatic turbulence changes the transport in the g mode case. A possibility is pointed out that the Kolmogorov spectrum appears in the g mode and the rippling mode turbulence.
View full abstract
-
Yoshiaki Kogure, Yosio Hiki
1988 Volume 57 Issue 1 Pages
125-133
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
A simulation has been made to determine the Peierls stress for a screw dislocation in neon, argon, krypton, and xenon model crystals. The Lennard-Jones (12–6) interatomic potential truncated at the third neighbors was chosen, and the ordinary atomic relaxation method was used for the simulation. The method of modified boundary condition was adopted to control the effect of the crystal surfaces. After the initial relaxation to obtain the static dislocation configuration, a shear strain was applied to the crystal and the relaxation was again made. The strain was successively increased until the critical shear strain to initiate the dislocation movement was found. The movement was detected by observing the Burgers vector density during the relaxation. The kinetic energy of crystal was also traced to observe the dislocation movement. The results obtained by the simulation were: the Peierls strain was τ
P⁄μ=(5.7±0.6)×10
−4 for all materials (τ
P: Peierls stress, μ: shear modulus); the Peierls stress τ
P was larger for heavier material, increasing from about 300 kPa for neon to 1000 kPa for xenon.
View full abstract
-
Yosio Hiki, Fujio Tsuruoka, Yoshiaki Kogure
1988 Volume 57 Issue 1 Pages
134-139
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
Measurements of the attenuation of pulsed longitudinal sound at megahertz frequencies have been made below and above the melting temperature in two kinds of hcp
4He crystals with the melting pressures of 32.5 and 60.0 atm. It was found that the attenuation in the solid increased gradually with temperature and then rapidly below the melting point; and that an appreciable amount of supercooling occurred in the liquid when the temperature was decreased. The dependence of the attenuation on the sound frequency revealed the overdamped resonance of crystal dislocations in solid helium. The temperature dependence of the attenuation in the premelting region of the solid was precisely studied. The results were analyzed on the basis of the vibrating dislocation model, and the density of dislocations in the crystal
Λ was determined as a function of temperature
T. The dependence was well represented as
Λ=
Λ0+
K⁄{1−(
T⁄
T0)}, where
Λ0,
K, and
T0 were constants. The characteristic temperature
T0 was close to or slightly lower than the melting temperature in two kinds of helium crystals.
View full abstract
-
V. Hizhnyakov
1988 Volume 57 Issue 1 Pages
140-146
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
A nonequilibrium statistical operator of a vibronic system in the representation of the configurational coordinate and the corresponding characteristic Wigner function are considered. In the formulas obtained, quadratic quantum fluctuations in the nonstationary state are expressed via integrals from the dynamical Green’s functions; the expressions at small and large times pass over into the Callen-Welton formula. The formalism proposed can be used to describe squeezed pulses.
View full abstract
-
Hirotaka Yamaguchi, Hiromoto Uwe, Tunetaro Sakudo, Etsuro Sawaguchi
1988 Volume 57 Issue 1 Pages
147-151
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Elastic properties of haxagonal BaTiO
3 have been investigated through measurements of elastic compliances by the composite-bar method. At the structural-phase-transition temperature
Ta∼215 K, the effective elastic compliance is found to exhibit a stepwise anomaly. Phenomenological theory of this phase transition is given by using a model that a silent
E2u mode in the high-temperature hexagonal phase might be the soft-phonon mode of which frequency vanishes at
Ta. At another transition temperature
Tc∼54 K, measured elastic compliances are found to exhibit a divergent increase. Together with other experimental evidences, the phase transition at
Tc is interpreted to be of a ferroelastic nature.
View full abstract
-
Gendo Oomi, Akio Shibata, Yoshichika \={O}nuki, Takemi Komatsubara
1988 Volume 57 Issue 1 Pages
152-155
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Lattice constants of the dense Kondo material CeCu
6 have been measured as a function of pressure up to about 100 kbar at room temperature and at 77 K. An anomaly is found in the compression curve at 77 K, which is attributed to monoclinic-orthorhombic phase transition induced by high pressure. A speculative pressure-temperature phase diagram of CeCu
6 is presented.
View full abstract
-
Gang Sun, Yohtaro Ueno, Yukiyasu Ozeki
1988 Volume 57 Issue 1 Pages
156-165
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Layered Potts models on a square lattice where ferromagnetic and antiferromagnetic bonds are regularly disposed are studied by means of an interface method, analytically and employing Monte Carlo simulations. They are classified into three types depending on the arrangement of bonds and the number of Potts spin states,
q: frustrated (FR) models that have frustration, degenerate (DG) models that have a high degree of degeneracy, and fitting models that have a unique ground state apart from the trivial degeneracy. Both FR and DG models are shown to exhibit phase transitions due to entropy gains, as previously predicted. The
q dependence of the interface tension and the critical temperature is clarified. We find that there are very similar properties between FR models and the corresponding Ising models. The models with
q>4 are suggested to undergo first order phase transitions.
View full abstract
-
Hiroyuki Mashiyama, Katsuhiko Hasebe, Sigetosi Tanisaki
1988 Volume 57 Issue 1 Pages
166-175
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The well-known type of the free energy to explain the incommensurate-commensurate transition in thiourea is reinvestigated by taking account of higher harmonics of the primary order parameter. The coupling between the seventh or nineth order harmonics and a quantity belonging to the identical representation can stabilize the sevenfold or ninefold superstructure against the incommensurate phase. It is also shown that an electric field induces the eightfold superstructure and that the obtained E-T phase diagram is consistent with experiments. An anomaly of the dielectric susceptibility at the tricritical point on the disordered-incommensurate transition line is presented.
View full abstract
-
Akira Kojima, Ken-ichi Tozaki, Toshiaki Ogawa, Tsutomu Takizawa, Tatsu ...
1988 Volume 57 Issue 1 Pages
176-187
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
The frequency dispersion curves of ac resistivity were obtained from 5 Hz to 13 MHz in superionic conductor Ag
3SI single crystal in the temperature region from 280 K to 110 K. The dynamic scaling of the ac resistivity has shown by the use of a scaling factor which is related to some characteristic time in the temperature region in each specimen; annealed β- and γ-phases and α-quenched. Various properties were derived from the high frequency limit of the shape of the master curves, and were discussed together with the results of the Arrhenius plot of the dc resistivity.
View full abstract
-
Tomio Iwasaki, Toshio Soda
1988 Volume 57 Issue 1 Pages
188-195
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
There are two sublattices A and B in hcp
3He in spite of the ferromagnetic state, because the hcp structure consists of two interpenetrating simple hexagonal Bravais lattices. We obtain the magnon excitation energy, and calculate 〈
Sz〉, the specific heat and so on near
T=0 by the spin wave theory. To extend the calculation for finite temperatures not near
T=0, the Green functions
GAA and
GBA are introduced. We derive a self consistent equation for 〈
Sz〉, using the spectral theorem, and compute 〈
Sz〉 and the Curie temperature
Tc, using RPA.
View full abstract
-
Yasumitsu Ohta, Kiyoshi Kawamura, Takuro Tsuzuku
1988 Volume 57 Issue 1 Pages
196-204
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The in-plane electron transport properties of stages-1 and -2 intercalation compounds of graphite with iodine-monochrolide (ICl) have been investigated between room and liquid helium temperatures. The characteristic
T2 term appearing in the temperature dependence of their resistivities is pointed out to originate from the discal equi-energy surface of out-of-plane mode phonons intersecting the long cylindrical Fermi surface, while the carrier scattering by in-plane longitudinal mode phonons showing a too steep dispersion diagram is neglegibly small. These compounds can be approximated to simple two-dimensional hole metals in the description of most transport effects. However, the appreciable magnetoresistance is observed even for the stage-1 which has just one band; this implies that the Fermi surface is trigonally warped so as to provide single anisotropic carriers in the basal plane.
View full abstract
-
Nobuya Mori, Noboru Nakamura, Kenji Taniguchi, Chihiro Hamaguchi
1988 Volume 57 Issue 1 Pages
205-216
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Magnetophonon resonance observed at high electric and magnetic fields in thin n
+nn
+ GaAs structure is shown to be well explained in terms of electric field induced inelastic inter-Landau-level scattering (IILLS). Splitting and inversion of the resonance peaks observed at high electric fields are explained by theoretical analysis of magnetoconductivity σ
xx based on Kubo formula. The general oscillatory structure of the magnetoconductivity is given by
(
Remark: Graphics omitted.),
which is valid for \bar
e<<1, where γ is the broadening factor, \barω
0=ω
0⁄ω
c, ω
0 and ω
c are the cyclotron and optic phonon frequencies, \bar
e=\sqrt2
eElB⁄hω
c,
lB is the classical cyclotron radius and
E is the magnitude of the electric field.
View full abstract
-
Yoshinori Nakane, Satoshi Takada
1988 Volume 57 Issue 1 Pages
217-229
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
We calculate the microwave conductivity due to phase mode taking into account impurity effects and long-range Coulomb interaction between the phason and quasi-particles (and/or free carriers). It is shown by using experimental results that the damping of the phason, which is expressed by the dc conductivity of quasi-particles (and/or of free carriers), is fairly large. We obtain the microwave conductivity (σ(ω)), taking into account this damping in the calculation of the self-energy of the phason Green’s function and explain frequency and delicate temperature dependences of σ(ω) of TaS
3 observed experimentally.
View full abstract
-
Hisashi Hiramoto, Shuji Abe
1988 Volume 57 Issue 1 Pages
230-240
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Dynamics of an electron in quasiperiodic systems is studied numerically. Calculations are carried out for the one-dimensional tight-binding model with diagonal or off-diagonal modulation obeying the Fibonacci sequence. The width of the wavepacket of an electron put on a single site at time
t=0 exhibits such an overall time evolution as \sqrt〈
Δx2〉∼
tα (0<α<1). The dynamical index α decreases continuously with increasing the modulation strength. This anomalous power-law diffusion is successfully interpreted in terms of renormalization group arguments in both the strong and weak modulation limits.
View full abstract
-
Teruhiko Mabuchi
1988 Volume 57 Issue 1 Pages
241-250
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Angle resolved electron energy loss spectra of alkali halide single crystals have been measured with primary energies from 50 to 950 eV, and incident and scattering angles from 20 to 80°. The loss spectra show not only the loss peaks which have been observed in the transmission measurements at higher primary energies but also the surface losses at 7.4 eV for KCl, 6.6 eV for KBr, 9.3 eV for NaF and 10.5 eV for LiF. The intensities of these surface loss peaks decrease both with the increase in primary energies and with the decrease in incident angles. These peaks are slightly below the first exciton excitation energy and attributed to the excitation of the surface exciton.
Moreover, it is found from the angular dependence of the intensities of the inelastically scattered electrons that the inelastic scattering is not the dipole but the impact scattering.
View full abstract
-
Akira Narita
1988 Volume 57 Issue 1 Pages
251-260
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The magnetic susceptibilities χ(
Q) are calculated numerically for some tight binding band structures with semiconducting property by means of Rath-Freeman method, in which the band structures are fitted to those obtained by APW method for LaN, LaP and GdN. From these calculations, the followings are found. (i) The band structure dependences of χ(
Q) are large. Those fitted to the LaN and LaP stabilize the antiferromagnetic state consistent to the experiments, while that to GdN the ferromagnet. (ii) The numerical χ(
Q) can be approximated very well by the decoupling expression, in which the matrix element is replaced by the averaged
Q-dependent matrix element
M(
Q) over the B.Z in the formula of χ(
Q). Its dispersion is almost determined by
M(
Q). (iii) In the constant matrix element case only the scatterings between the nearest bands to the Fermi level are important for χ(
Q). But, in inclusion of matrix element effect those between sufficiently separated bands also become very important.
View full abstract
-
Hiroko Aruga, Tetsuji Tokoro, Atsuko Ito
1988 Volume 57 Issue 1 Pages
261-266
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The frequency dependence of paramagnetic-to-spin-glass transition temperature
Tg(
f) for a short-range Ising spin-glass, Fe
0.5Mn
0.5TiO
3, over a wide frequency range extending to ∼10
11 Hz has been examined by the ac-susceptibility measurement (2.0×10 Hz≤
f≤6.65×10
4 Hz), the Mössbauer measurement (corresponding to
f∼6×10
6 Hz) and the neutron scattering measurement (corresponding to
f∼10
11 Hz). The frequency-dependent phenomenon is analyzed using the Fulcher law, the power law for transition at zero temperature and the power law for a finite transition temperature. All laws appear to account for the observed behavior equally well. By examining the values of the parameters obtained from the analysis of experimental data closely, we show that the power law for a finite transition temperature,
f=
f0[(
Tg(
f)−
T*)⁄
Tg(
f)]
zν with
f0=2.4×10
13 Hz,
zν=11.5 and
T*=20.5 K, is more appropriate than the other laws.
View full abstract
-
Hitoshi Yamazaki
1988 Volume 57 Issue 1 Pages
267-274
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Spin-wave relaxation rate in the quasi-two-dimensional ferromagnet (CH
3NH
3)
2CuCl
4 are studied by parallel pumping experiment. Magnon relaxation rate is determined as a function of wave number from zero to the Brillouin-zone-boundary in the direction perpendicular to the ferromagnetic layers and as a function of θ
k, which is the angle between the magnon wave vector and the direction of the static magnetic field. Temperature dependence of the relaxation rate is proportional to
T2. Magnetic excitation is found at frequencies below the spin-wave band. Phonon bottleneck effect is discussed to explain the magnon relaxation in this crystal.
View full abstract
-
Takanori Fukami, Shin Akahoshi, Kenzi Hukuda
1988 Volume 57 Issue 1 Pages
275-277
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The authors observed the
77Se hyperfine (hf) components of ESR spectrum of SeO
43− radicals doped in 94%-deuterated NH
4H
2PO
4 (D
0.94ADP) and compared the result with those for D
xADP (0≤
x≤0.70) crystals. In the paraelectric phase no remarkable deuteration effect was observed. In the antiferroelectric (AFE) phase, on the other hand, a new type of angular dependence of the hf line-position was found between about 185 K and
Tc (236 K). The results mean that the crystal field of the AFE host crystal which distorts the SeO
43− into the AFE configuration depends on temperature remarkably in the AFE D
0.94ADP.
View full abstract
-
Yu-ichi Miura, Masaaki Takashige, Terutaro Nakamura, Takao Furubayashi ...
1988 Volume 57 Issue 1 Pages
278-281
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
One of the glass-like behaviors, i.e. the frequency dependent minimum of the dielectric constant ε′ in milli-Kelvin region in PbTiO
3 has been measured as a function of grain size. The slope (dε′⁄d
T) in the region
T<
Tmin first increases with grain size, shows a distinct maximum at the grain size 10
2 nm, then decreases, where
Tmin is the temperature giving the dielectric constant minimum. This result strongly suggests that a large ideal perfect single crystal of PbTiO
3 will not show any glass-like behavior.
View full abstract
-
Akio Miyazaki, Yasuharu Makita
1988 Volume 57 Issue 1 Pages
282-291
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
The dielectric constant of NaNH
4SeO
4·2H
2O along the
c axis under stress-free and clamped conditions, ε
33f and ε
33c, were experimentally determined, and its elastic stiffnesses under constant electric field and constant electric polarization conditions,
c66E and
c66P, and other elastic stiffnesses were also determined experimentally. It was clarified that both ε
33c and 1⁄
c66P(
s66P) follow the Curie-Weiss law, but the phase transition in NaNH
4SeO
4·2H
2O is caused by predominant dielectric instability more than elastic instability. It was predicted basing on the Landau theory that one of three elastic shear stiffnesses,
c66E, shows discontinuous behaviour at the Curie temperature
Tc, but the other two,
c44E and
c55E, show continuous behaviours at
Tc, if the phase transition is of first order. The prediction was confirmed to be the case by the experimental results.
View full abstract
-
Yosuke Kayanuma
1988 Volume 57 Issue 1 Pages
292-301
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Numerical calculations of the resonant secondary radiation spectrum of the strongly coupled localized electron-phonon system are presented both for the stationary and transient responses. The time evolution of the transient response makes it clear how the line shape of the stationary radiation spectrum is formed in accordance with the three characteristic time-scale, namely, the phase relaxation time, the energy relaxation time and the population decay time.
View full abstract
-
Takasi Endo, Takao Muramoto
1988 Volume 57 Issue 1 Pages
302-305
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Transient absorption of the ruby R
1 line was measured as a function of time
t. Although the optical Bloch equations predict that the transient absorption
A(
t) is asymptotically proportional to
t−1⁄2, it was found that
A(
t) is asymptotically proportional to
t−1. This discrepancy is explained by a truncation of the homogenous line shape at the line wings.
View full abstract
-
Takashi Fujikawa
1988 Volume 57 Issue 1 Pages
306-319
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
In this work, a formal theory of electron scattering is presented from first principles by use of the many-body scattering theory. We investigate both the elastic and inelastic scattering of an electron from solids. In particular the correction terms due to elastic scattering in solids are considered to the Bethe’s amplitude in high energy electron energy loss spectra; explicit formulas for seven different correction terms are given here. Other complicated scattering processes, for example, in which an electron suffers a core and a plasmon excitation successively, are also studied here. The optical potential to describe elastic scattering is also discussed within the present theoretical framework.
View full abstract
-
Takashi Fujikawa, Kouji Tashiro, Wolfgang Krone, Gunter Kaindl
1988 Volume 57 Issue 1 Pages
320-328
Published: January 15, 1988
Released on J-STAGE: May 29, 2007
JOURNAL
RESTRICTED ACCESS
In this work, iodine L
1-XANES of (CH(IBr)
y)
x excited by two linearly polarized X-ray are analyzed by use of the short-range order full multiple scattering calculations. The XANES analysis for
E⊥
c polarization (normal to the chain axis) gives us the information on the I–C correlation. One useful information obtained here is that the nearest I–C distance is longer than the sum of the van der Waals radii of I and C. This result can explain the increase of the anisotropy of the electric conductivity by IBr doping. Our XANES analyses can also predict charge distribution on polyanions I
2Br
− as
q1=−0.5∼−0.7,
q2=0.2∼0.3 and
q3=−0.5∼−0.7, where I
(q1)I
(q2)Br
(q3),
q1+
q2+
q3=−1. The observed sharp peak in
E⁄⁄
c XANES is found to be due to the absorption by the end iodine atom.
View full abstract
-
Jun-ichi Kasai, Toshio Hyodo, Kunio Fujiwara
1988 Volume 57 Issue 1 Pages
329-341
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Momentum distribution of annihilation γ rays from several alkali halide crystals has been measured using high resolution 1D angular correlation apparatuses. Formation of Bloch-type positronium (Ps) in NaBr and RbCl has been newly confirmed, while no evidence for it has been seen in LiF, KF, and CsI. Effective mass of the Ps in the Bloch state has been determined by analyzing the low temperature behavior of the Ps momentum distribution. The effective mass is larger than the free Ps mass in vacuum in all the alkali halides investigated. Detailed analysis of the temperature dependence of the Ps momentum distribution has been made on KI and KBr. Temperature induced transition to the self-trapped state as previously reported in NaF and KCl has been observed also in these materials.
View full abstract
-
Sh\={u}ichi Sat\={o}, Yoshihiro Ohmura
1988 Volume 57 Issue 1 Pages
342-352
Published: January 15, 1988
Released on J-STAGE: June 01, 2007
JOURNAL
RESTRICTED ACCESS
Theoretical study of γ-ray inelastic scattering by
K-shell electrons for the case of
qa∼1 is presented, where h
q is the momentum transfer of the primary γ-ray and
a is the orbital radius of the
K-shell electron. Details of calculation for the contribution of
A2-term to the scattering,
A being the vector potential, are given a using a single orthogonalized plane wave for the wave function in the scattering state. The present theoretical result is compared with the experimental one obtained by Namikawa and Hosoya (NH) (Phys. Rev. Lett.
53 (1984) 1606): scattering of 59.57 keV γ-rays by
K-shell electrons of Cu and Fe. The C peak and R peak found experimentally by NH are reproduced theoretically though the height of the R peak is 1/3 of that of the experimental result by NH.
View full abstract