巻号一覧
65 巻, 3 号
選択された号の論文の42件中1～42を表示しています
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Hideaki Ujino, Miki Wadati専門分野: Mathematical methods in physics.
1996 年 65 巻 3 号 p. 653-656
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありAn algebraic construction of the eigenstates for the quantum Calogero modelis investigated. Extending the method of Lapointe and Vinet, weconstruct the eigenstates for the second conservedoperator of the quantum Calogero model.All the eigenstates can be factorizedinto symmetric polynomials which we call “Hi-Jack symmetric polynomials”and the ground state wave function.The conjectured formula for the eigenvalue of the second conserved operatoris confirmed.The Hi-Jack polynomials are strong candidates for the orthogonalbasis of the quantum Calogero model.抄録全体を表示PDF形式でダウンロード (285K) -
Keiko Emi, Toshifumi Tsukamoto, Hiroyuki Hirano, Haruhiko Mamada, Yosh ...専門分野: Experimental methods and instrumentation for elementary-particle and nuclear physics.
1996 年 65 巻 3 号 p. 657-660
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありWe studied dE/dx in a small-celldrift chamber filled with a gas mixture of 50% He and 50% C2H6. The dE/dx resolution, measured in terms of the 80% truncated mean of 41 layer samples, was 5.2% when the incident angle of the track with respect to the wire direction was 45°.The βγ dependence showed asmaller relativistic rise than in the case of P-10 gas.At an incident angle of 90°, we observed gas gain saturationdue to the space charge effect. Although thismakes the βγ dependence of dE/dx weaker, thedE/dx resolution was improved. As a result, a π-K separation of 2σ is achieved at all incident anglesfor 2 GeV/c tracks.抄録全体を表示PDF形式でダウンロード (274K) -
Susumu Shimomura, Nozomu Hamaya, Yasuhiko Fujii専門分野: Equations of state, phase equilibria, and phase transitions.
1996 年 65 巻 3 号 p. 661-663
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありUsing synchrotron radiation, we have performed a high-resolution X-ray diffraction study of a phase transition between the incommensurate phase and the commensurate phase characterized by the wave vector q=3c*/7 in [N(CH3)4]2MnCl4 under pressure. The pressure dependence of the wave vector q exhibits an ``incomplete devil's staircase.'' The high-resolution capability of the synchrotron radiation reveals that the incommensurate satellite reflection shows an asymmetric and broad line shape along the modulation direction, while the q=3c*/7 commensurate superlattice reflection is symmetric and its width is equal to the instrumental resolution. Such a profile of the incommensurate satellite reflection is found to depend on the history of the crystal.抄録全体を表示PDF形式でダウンロード (267K) -
Takafumi Kita専門分野: Quantum fuids and solids: liquid and solid helium.
1996 年 65 巻 3 号 p. 664-666
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe kinetic energy of a charged system is calculated for Mermin's one-particledensity matrix of Fermi superfluids. The final expression consistsof two separate contributions from the center-of-mass and the relative motionsof an effective bound-state wave function. The relative part naturally includes coupling of the intrinsic orbital angular momentum densityto the magnetic field.For 3He-A at T=0, its magnitudeis (h/ 2) × (number density), in agreement with Ishikawa's result.抄録全体を表示PDF形式でダウンロード (270K) -
Takami Tohyama, Sadamichi Maekawa専門分野: Electron states in condensed matter.
1996 年 65 巻 3 号 p. 667-670
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe electronic states of newly developed cuprate superconductors with apical halogen are examined by means of the ionic and cluster model approaches developed in a previous study for other cuprates [Y. Ohta, T. Tohyama, and S. Maekawa, Phys. Rev. B 43 (1991) 2968]. We find two features that differ from those of other cuprates: (i) small dielectric constant and (ii) large hopping energy of electrons in the CuO2 plane. Both features are of primary importance for understanding the dependence of the energy gap and the superexchange interaction on the material of the parent compounds. As in other cuprates, the superconducting critical temperature Tc is found to be well correlated with the stability of the Zhang-Rice local singlet in the CuO2 plane.抄録全体を表示PDF形式でダウンロード (358K) -
Takako Iizuka–Sakano, Yutaka Toyozawa専門分野: Electron states in condensed matter.
1996 年 65 巻 3 号 p. 671-674
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe neutral (N)-to-ionic (I) transition with dimerization, found inorganic charge transfer compounds with mixed stacking, has beenstudied using a self-consistent theory which takes exact account oflong-range Coulomb interactions but neglects interchain coupling.The unrestricted Hartree-Fock approximation gives a set of optimallymixed donor-acceptor bands with optical gap which bifurcatesin the I phase.The dimerization is ascribed to the electrostatic instability, ratherthan to the distance dependence of the intermolecular electronic transferenergy as is usually done.The phase diagram for the first-order N-I transition with dimerizationand discontinuous change of charge transfer is presented on theparameter plane of the redox potential and the transfer energy.The results of numerical calculations are consistent with the experimental data for tetrathiafulvalene-chloranil compound.抄録全体を表示PDF形式でダウンロード (321K) -
Yoshifumi Onishi, Yoji Ohashi, Yasunori Shingaki, Kazumasa Miyake専門分野: Superconductivity.
1996 年 65 巻 3 号 p. 675-678
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありEffects of nonmagnetic impurities with unitarity scattering in two-dimensional d-wave superconductors are investigated by the numerical diagonalization of finite-size systems of up to 35×35 sites. It is shown that a localized state with almost zero excitation energy is formed around an impurity site if it is isolated. However, its localized state is extended in real space along the direction of the node of the d-wave gap, so that the localized states of adjacent impurities easily interfere with each other forming a kind of impurity band, i.e., resonance states around the zero energy. It is also pointed out that there exists a strong association between the resonance density of states due to impurity scattering in the unitarity limit and the so-called zero-bias anomaly of tunneling conductance.抄録全体を表示PDF形式でダウンロード (328K) -
Kazuyuki Matsuda, Yoh Kohori, Takao Kohara専門分野: Superconductivity.
1996 年 65 巻 3 号 p. 679-682
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありWe have carried out 101Ru NQR measurements of URu2Si2 in zero magnetic field in the temperature, T, range from 0.16 K to 26 K. From the NQR spectrum, the electric quadrupole interaction parameters were determined to be ν_Q =5.72 MHz and η =0. The nuclear spin-lattice relaxation rate, 1/T1, decreases drastically below 17.5 K. This decrease is associated with antiferromagnetic ordering. In the superconducting state, 1/T1 has no coherence peak just below Tc=1.2 K, and decreases in proportion to T3 with no deviation down to 0.2 K, which indicates the existence of line nodes in the superconducting energy gap.抄録全体を表示PDF形式でダウンロード (296K) -
Yasusi Koyama, Yositake Takane, Hiromichi Ebisawa専門分野: Superconductivity.
1996 年 65 巻 3 号 p. 683-686
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありMesoscopic fluctuations of the DC Josephson currentin a dirty SNS junction (S: superconductor, N: normal conductor)are studied numericallyin the presence of barrier potentialsat the NS interfaces, which reducethe Andreev reflection probability.The results show that the critical-current fluctuationsin the long-junction limit are suppressed asthe Andreev reflection probability decreaseswhile those in the short-junction limit are relativelyinsensitive to reductions in the Andreev reflection probability.Therefore, the effect of incompleteAndreev reflection is significant in the long-junction limit.We show that the quantitative difference between our previoustheory and the experimental results of Takayanagiet al. is well explained by taking the effectof incomplete Andreev reflection into account.抄録全体を表示PDF形式でダウンロード (285K) -
Flordivino Basco, Hiroshi Kohno, Hidetoshi Fukuyama, Ganapathy Baskara ...専門分野: Superconductivity.
1996 年 65 巻 3 号 p. 687-690
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありA new possible treatment of large-amplitude gauge-field fluctuations around theslave-boson mean-field theory for the t-J model has been proposed by attachinggauge flux to spinons and holons and then by treating them as g-ons which respectthe time-reversal symmetry. Using the thermodynamic distribution function ofg-ons, the optimum exclusion statistics has been determined in the planeof doping rate and temperature. The results indicate that slave fermions are favoredat low doping while slave bosons at high doping with intermediate statistics inbetween.抄録全体を表示PDF形式でダウンロード (288K) -
Makoto Honda, Tadashi Shibata, Koichi Kindo, Shunji Sugai, Tetsuya Tak ...専門分野: Magnetics resonances and relaxations in condensed matter; MÖssbauer effect.
1996 年 65 巻 3 号 p. 691-694
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありElectron spin resonance measurements were performed on a single crystal of the one-dimensional antiferromagnet CuGeO3 which shows the spin-Peierls transition. The signals in the paramagnetic phase show a strong interchain exchange interaction and the angular dependence of the g-value is explained by a tetragonal field. Decrease of absorption intensity due to formation of the energy gap below the transition temperature is found. The angular-dependent linewidth below the transition temperature shows a different pattern from that of the paramagnetic phase. The temperature and angular dependence of the linewidth are discussed by taking account of the one-dimensional diffusion process and spin-Peierls system.抄録全体を表示PDF形式でダウンロード (278K) -
Yutaka Itoh, Masahiro Matsumura, Hideki Yamagata, Hiroyuki Miyamoto専門分野: Magnetics resonances and relaxations in condensed matter; MÖssbauer effect.
1996 年 65 巻 3 号 p. 695-698
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありWe report the temperature(T)-dependence of the planar 63Cu nuclear spin-lattice relaxation rate, 1/T1, both at the Cu(A)-site (77.3K≤ T≤ 500K) and at the Cu(B)-site (77.3K≤ T≤ 300K) in the high-Tc Cu oxide, La1.80Sr0.20CuO4 (Tc-- 30K), measured by the Cu NQR spin-echo technique. We found that 1/T1 at the Cu(B)-site is different from that at the Cu(A)-site, and that 1/T1 at the Cu(A)-site has a superlinear T-dependence in the T-range of 300-- 500K. Comparisons of the present 1/T1 are made with the data for other systems. The difference in 1/T1 between two Cu sites is discussed from the viewpoint of local inhomogeneous electronic states.抄録全体を表示PDF形式でダウンロード (304K) -
Masahiro Matsumura, Yutaka Itoh, Hiroshi Yasuoka, Yutaka Ueda, Hideki ...専門分野: Magnetics resonances and relaxations in condensed matter; MÖssbauer effect.
1996 年 65 巻 3 号 p. 699-702
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありNuclear spin-lattice relaxation rate 1/T1 of 63Cu was measured from 100K to 800K in La1.85Sr0.15CuO4, and is compared with the previous result of the parent compound La2CuO4. There exists a distinct difference in the values of 1/T1 at high temperatures between the metallic La1.85Sr0.15CuO4 and the insulating La2CuO4. The contribution of an antiferromagnetic mode around q-- Q=(π/a, π/a) to 1/T1 (1/T1)AF was evaluated. The extracted rate (1/T1)AF shows a broad peak at T*-- 300K. The value of (1/T1T)AF follows the Curie-Weiss law C/(T+θ ) above and below T*. This result suggests a crossover from the high-temperature regime with negative Weiss temperature θ to the low-temperature regime with positive θ .抄録全体を表示PDF形式でダウンロード (296K) -
Kazuo Gesi専門分野: Dielectric properties and materials.
1996 年 65 巻 3 号 p. 703-705
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe dielectric properties of single-crystal CH3NH3AlBr4 have been studied. The crystal belongs to the tetragonal system at room temperature. It shows ferroelectricity along the a-direction below the Curie temperature Tc=76.6K. The dielectric constant along the a-direction obeys a Curie Weiss law above Tc with the Curie constant being 3.7× 102K. The spontaneous polarization measured by means of 50Hz hysteresis loop at 64K is 6.6× 10-3, C/m2. Besides the ferroelectric transition, a first order structural phase transition is found at about 250K.抄録全体を表示PDF形式でダウンロード (201K) -
Munetaka Taguchi, Akio Kotani専門分野: Optical properties and condensedmatter spectroscopy and other interactions of matter with particles and radiation.
1996 年 65 巻 3 号 p. 706-709
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe excitation spectrum of spin-dependent X-ray emission of Mn compounds is studied theoretically in terms of a coherent second-order optical process. It is shown that the effects of the core-hole potential and the term-dependent lifetime of the final states play an important role in Mn K-edge excitation spectra of MnF2.抄録全体を表示PDF形式でダウンロード (280K) -
Motoji Ikeya, Shunji Takaki, Dan Takashimizu専門分野: Geophysics, astronomy, and astrophysics.
1996 年 65 巻 3 号 p. 710-712
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありElectric field effects on fish and worms have been studied assuming that the seismic animal anomalous behaviors (SAABs) witnessed prior to the Hansin Earthquake were caused by seismic electric current. Japanese minnows, guppies and loaches responded to the current and aligned perpendicular to the field direction and earthworms swarmed, which are forms of SAABs, at a current density of J=0.1-- 1A/m2 presumably to reduce the effects of the field, F. A mathematical model of a fault was used to express the seismic stress, σ (t) corresponding to a fault displacement, D(t). An electromagnetic model of a fault, where a bound charge density, q which compensate the piezoelectric polarization, appears due to the release of seismic stress is used to derive dq/dt=-α (dσ /dt)-q/ε ρ, F=q/ε and J=F/ρ '. Using the piezoelectric coefficient, α, dielectric constant, ε and the resistivity, ρ of bedrock granite and ρ ' of water gives J=1A/m2 in concordance with the experiments.抄録全体を表示PDF形式でダウンロード (355K) -
Kimiaki Konno, Hiroshi Kakuhata専門分野: Mathematical methods in physics.
1996 年 65 巻 3 号 p. 713-721
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありA coupled integrable, dispersionless system is solved by the inverse scattering method.Three types of solitons are uncovered.Novel solitonic phenomena are recorded.抄録全体を表示PDF形式でダウンロード (365K) -
Yasushi Komori, Miki Wadati専門分野: Mathematical methods in physics.
1996 年 65 巻 3 号 p. 722-724
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe quantum one-dimensional massless Thirring model is studied. A transformation which casts the massless Thirring model into a quadratic form is found. The transformed field operators satisfy interesting commutation relations, fermion anti-commutation relations among the same kinds of fields and anyon-like commutation relations between different kinds. Bethe Ansatz wavefunctions are constructed algebraically using the transformation and the commutation relations in coordinate space.抄録全体を表示PDF形式でダウンロード (166K) -
Hitoshi Imaoka, Yasuhiro Kasai専門分野: Statistical physics and thermodynamics.
1996 年 65 巻 3 号 p. 725-731
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありA duality of the antiferromagnetic triangular Ising model, a fully-frustrated model, is investigated. Using Onsager's recipe, a dual model with complex coupling constants on a honeycomb lattice is obtained. By Kasteleyn and Fortuin's transformation of the partition function of the dual model, we find a percolation system whose cluster sizes are restricted to be even. This is a new realization on the frustration of the original Ising model, which reflects a dimer character of frustrated spin clusters. Those results are extended to the Potts model.抄録全体を表示PDF形式でダウンロード (545K) -
Kenn Kubo, Ken–ichi Ohwi専門分野: Statistical physics and thermodynamics.
1996 年 65 巻 3 号 p. 732-735
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありWe extend the proof for the existence of long-range order(LRO) in the frustrated XXZ model with nearest and next nearest neighbor interactions on the square lattice. It is shown that the Néel LRO exists in the frustrated XY model when frustration is weak.抄録全体を表示PDF形式でダウンロード (267K) -
Hiroshi Takano専門分野: Statistical physics and thermodynamics.
1996 年 65 巻 3 号 p. 736-740
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe non-equilibrium critical dynamics of the Baxter modelis studied through Monte Carlo simulations.The single-spin-flip stochastic dynamics is introducedon the basis of the formulation of the modelas an Ising-type model on the square lattice with next-nearest-neighbor and four-spin interactions.At several points on the critical line, the dynamic critical exponent z and the critical exponent \bar λc, which characterizes the non-equilibrium critical relaxation, are estimatedfor the two order parameters of the model, the magnetization and the polarization. For both order parameters, the estimated \bar λc varies systematically along the critical line. On the other hand, the estimated z is almost constant. This suggests thatwhile the exponent z is universal, the exponent \bar λcis not.抄録全体を表示PDF形式でダウンロード (339K) -
Rama Shanker, Reinhild Bilau Faust専門分野: Atomic and molecular collision processes and interactions.
1996 年 65 巻 3 号 p. 741-744
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe present experimental results indicate that the physical origin of the continuum electrons produced in 75--1050, keV Krn++Xe collisions (n=1-3) may be located in the KrXe quasimolecule. A direct radial- or rotational-type of coupling between the highly promoted MOs and the continuum states is suggested to be responsible for the observed nature of the exponential decay of the continuum electrons as a function of their energies. A simple empirical relation describing the cross sections of the electrons that are emitted due to a dynamical variation of the molecular-orbitals and have a broadened spectra beyond the classical cut-off frequency, is shown to yield a fair agreement with the observed data.抄録全体を表示PDF形式でダウンロード (336K) -
Yuichi Yatsuyanagi, Tadatsugu Hatori, Tomokazu Kato専門分野: The physics of plasmas and electric discharges.
1996 年 65 巻 3 号 p. 745-759
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありOur research is aimed to derive the macroscopic equation of motionof a vortex-current filament, in which electric current and vorticity coaxially exist. The macroscopic equation of motion of vortex filaments without the electric current has been developed by D. W. Moore and P. G. Saffman. To derive the new equations of motion of the vortex-current filament, we follow their methods and obtain the result correct to the terms inversely proportionnalto the square of radius of curvature.The resulting equations of motion contain both the hydro- andmagnetohydro-dynamic effects. Our result can be elucidated by comparing with the result obtained by V. S. Mukhovatov and V. D. Shafranov inthe force balance analysis in Tokamak. The cut-off Biot-Savart integralapproximation derived by E. D. Siggia is also useful in our MHD formulation.抄録全体を表示PDF形式でダウンロード (913K) -
Kimitaka Itoh, Sanae–I. Itoh, Atsushi Fukuyama, Masatoshi Yagi専門分野: The physics of plasmas and electric discharges.
1996 年 65 巻 3 号 p. 760-764
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありCirculating power for the sustenance and profile control of the steady state tokamak plasmas is discussed. The simultaneous fulfillment of the MHD stability at high beta value, the improved confinement and the stationary equilibrium requires the rotation drive as well as the current drive. In addition to the current drive efficiency, the efficiency for the rotation drive is investigated. The direct rotation drive by the external torque, such as the case of beam injection, is not efficient enough. The mechanism and the magnitude of the spontaneous plasma rotation are studied.抄録全体を表示PDF形式でダウンロード (429K) -
Tatsuhiro Yogi専門分野: Structure of liquids and solids; crystallography.
1996 年 65 巻 3 号 p. 765-770
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありA new method is proposed which should lead to correct equations of motion for rigid bodies and provide improved numerical stability and precision for computer simulation studies of classical molecules. New angular velocities \dot α and \dot β are introduced for generating an orthogonal matrix enabling the transformation between principal angular velocities and time derivatives {\dot α}, {\dot θ} and {\dot β}. Time derivative of Euler angle φ is represented by a linear combination of new angular velocities. This transformation and linear combination allows us to remove the singularities and spurious behavior near θ=π/2 and to produce the trajectory of three angular velocities continuously.The method introduced here reveals that the structure and properties of diatomic molecules are independent of the value of γ, which denotes the ratio of I3 to I1 of a molecule.Application of this method to diatomic liquids such as nitrogen enables time variation of angular velocities and their continuity to be described.抄録全体を表示PDF形式でダウンロード (429K) -
Jun–ichiro Suda, Tomoo Nakayama, Akio Nakahara, Mitsugu Matsushi ...専門分野: Structure of liquids and solids; crystallography.
1996 年 65 巻 3 号 p. 771-777
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありPotassium dichromate (K2Cr2O7) grown in gelatin has been found to exhibit five morphological phases, i.e., right- or left-handed spiral, spherulite, square polelike, platelike and DLA-like crystals when varying the initial concentrations of K2Cr2O7 and gelatin. The results are summarized in a morphological phase diagram. Although we reported in our previous letter that spiral crystals obtained were all right-handed, only a few left-handed spiral crystals have also been observed in a specific subregion of the spiral growth region in the phase diagram. Square polelike crystals have shown tendency to grow and fuse together side by side in a region adjacent to the spiral growth in the phase diagram. This strongly suggests that spirals are composed of small square polelike crystals fused together. It is conjectured that right-handed triple helices of collagen molecules constituting gelatin-gel perturb the growth process to form right-handed spirals obtained mainly in the present experiments.抄録全体を表示PDF形式でダウンロード (1977K) -
Neutron Scattering Studies of the Effects of Uniaxial Stress and Ageing on the β_1--Cu--Al--Zn AlloyAkira Nagasawa, Miyoko Yamada, Yukio Morii専門分野: Lattice dynamics and crystal statistics.
1996 年 65 巻 3 号 p. 778-781
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありIn the present paper, we give the results of neutron scattering studies on the β 1-phase of Cu--17.0Al--14.3Zn alloy. Our interests are mainly concerned with both phonon dispersion relations and elastic scattering anomalies of single crystal specimens: the one is under the [001] compressive stress and the other after ageing. Behaviours of the [110]TA1 phonon branch indicate that the [001] stress enhances the lattice instability relating to the β 1-to-martensite transition. The 2/3q0-peak is not due to any martensites. The ageing at 373, K for 7 days has no influence on the [110]TA1, [111]LA and [112]TA phonon branches and also on the 2/3q0- and ω -like peaks. The result means that the ω -like peak is not due to the ω -phase formation. Both the 2/3q0- and ω -like peaks would be caused from a certain kind of regular arrangements of vacancies in the L21-type β 1-phase.抄録全体を表示PDF形式でダウンロード (376K) -
Ryõen Shirasaki専門分野: Electron states in condensed matter.
1996 年 65 巻 3 号 p. 782-791
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありIn this paper we analytically study the effects of the lattice discreteness on the electron band in the SSH model. We propose a modified version of the TLM model which is derived from the SSH model using a continuum approximation. When a soliton is induced in the electron-lattice system, the electron scattering states both at the bottom of the valence band and the top of the conduction band are attracted to the soliton. This attractive force induces weakly localized electronic states at the band edges. Using the modified version of the TLM model, we have succeeded in obtaining analytical solutions of the weakly localized states and the extended states near the bottom of the valence band and the top of the conduction band. This band structure does not modify the order parameters. Our result coincides well with numerical simulation works.抄録全体を表示PDF形式でダウンロード (680K) -
Kazuo Miura, Tamifusa Matsuura, Yoshihiro Kuroda専門分野: Electron states in condensed matter.
1996 年 65 巻 3 号 p. 792-799
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありWe investigate effects of the antiferromagnetic spin fluctuation on the electronic states in the d-p model within the approximation including the most dominant terms in the perturbational expansion from the large limit of spin-orbital degeneracy N (1/N-expansion). Since such effects manifest themselves only through the higher order terms in the 1/N-expansion, we add an inter-site exchange interaction J_S artificially to the Hamiltonian as the 0-th order term and examine effects of the inter-site exchange correlations on the electronic states. We find that the local d-holes and the free p-hole are hybridized coherently to form the ingap states with a large Fermi surface, essentially in the same way as in the case with J_S=0 studied earlier, but the band width of the ingap states is suppressed appreciably by the antiferromagnetic spin fluctuation eventually to vanish at a certain amount of carrier doping near half-filling and with the less doping no self-consistent solution is found.抄録全体を表示PDF形式でダウンロード (544K) -
Chikara Sugiura専門分野: Electron states in condensed matter.
1996 年 65 巻 3 号 p. 800-802
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありWith a high-resolution two-crystal vacuum spectrometerequipped with beryl crystals, the Ge Lα emission and Ga Lα emission spectra in fluorescencehave been measured for Ge, GeO_2, GaP, GaAs and Ga_2O_3. The measuredLα emission spectra consist of a prominent peak Lα1, 2and its high-energy structure, and are slightly influenced by chemicalbonding. The Lα emission spectrum of Ge is compared with availablemultiplet calculations for Ge Lα1, 2 satellites. Thehigh-energy structure is primarily attributed tothe satellites as a result of multiple ionizations.抄録全体を表示PDF形式でダウンロード (273K) -
Tomoh Ueda, Kanya Kusano, Minoru Sasaki, Masasi Inoue専門分野: Electronic transport in condensed matter.
1996 年 65 巻 3 号 p. 803-810
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありOne-dimensional transport equations for pulsed-laser induced space-charge distributions in GaAs crystals have been computed using a finite difference procedure by two models; (a) Model A for i-GaAs with an applied dc electric field under a uniform illumination over the crystal and (b) Model B for n- and i-GaAs without the electric field under a half illumination to simulate the “transient thermoelectric effect” (TTE). With Model A, the temporal and spatial evolutions of restored space-charge density of photoexcited electrons and holes are obtained, from which an induced electric field is found to oscillate with a single frequency of plasma oscillations (0.3--2, THz), in satisfactory agreement with reported experiments. Model B calculations have revealed that near the boundary between the illuminated and non-illuminated regions, the appreciable enhancement of space-charge densities and induced electric fields are observed, which diffuse or drift toward a positive x direction, showing characteristic damping oscillations with two frequency components f0 due to the doped donor electrons and f1 due to the doped and photoexcited electrons of plasma oscillations. Furthermore, the induced TTE voltages measured across both ends of the crystal without dc electric field are simulated to show similar coherent plasma oscillations.抄録全体を表示PDF形式でダウンロード (630K) -
Kazuhito Tsukagoshi, Masaru Haraguchi, Sadao Takaoka, Kazuo Murase専門分野: Electronic transport in condensed matter.
1996 年 65 巻 3 号 p. 811-817
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありWe investigate the transport properties in various antidot lattices.It is found that the fundamental peak on resistivity is determined by the conductivity perpendicular to the current flow direction in the case of smaller diagonal component of conductivity tensor than the off-diagonal one.Moreover, the peaks of conductivity are explained by the runaway trajectory, on which the electrons diffuse along the antidot array like as skipping over the antidots when the cyclotron diameter of electron corresponds to the antidot period, and the conductivity along the antidot period is enhanced.This is the origin of the fundamental peak in the commensurability oscillations.抄録全体を表示PDF形式でダウンロード (725K) -
S. Mandal, A. Ghosh専門分野: Electronic transport in condensed matter.
1996 年 65 巻 3 号 p. 818-822
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe frequency and temperature dependence of the complex ac electrical properties are reported in the frequency range 0.1-100, kHz and in the temperature range 80-300, K for the lead vanadate glass in a wide composition range (50-90, molexperimental results are analysed with reference to the theoretical models based on quantum tunneling through a barrier and classical hopping over a barrier. It is observed that the large polaron tunneling is the dominant charge transfer mechanism for the glass compositions with 80 and 90, mol\classical hopping plays significant role in the charge transfer mechanism for other glass compositions. Possible reasons for the change of loss mechanism with compositions are suggested.抄録全体を表示PDF形式でダウンロード (408K) -
Yoji Ohashi専門分野: Superconductivity.
1996 年 65 巻 3 号 p. 823-839
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありA novel proximity effect, that the d-wave superconductivity induces a different symmetric order parameter in the normal metal side, is investigated for the normal metal (N)-d-wave superconductor (S) junction in the clean limit. The induced superconductivity is obtained self-consistently on the basis of the quasi-classical theory and the condition of this effect to occur is clarified. Our result shows that the deformation of the pair amplitude and the direction of the NS boundary with respect to the phase of the d-wave superconductivity are crucial in this phenomenon. A characteristic structure appearing in the local density of states due to this proximity effect is also examined comparing with the conventional case.抄録全体を表示PDF形式でダウンロード (1126K) -
Guido Eilers, Masaaki Matsui専門分野: Magnetic properties and materials.
1996 年 65 巻 3 号 p. 840-843
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありIn this study we report about the magnetic properties of(CuIn)1-xMn2xTe2. The magnetizationmeasurements onsamples with Mn concentrations up to x=0.5 showed a similar behavioras other diluted magnetic semiconductors. An analysis of the spin glassfreezing temperatures suggests a farther reaching and strongerinteraction between the Mn ions than in the corresponding II-VIcompounds Zn1-xMnxTe andCd1-xMnxTe.抄録全体を表示PDF形式でダウンロード (316K) -
Kazutoshi Ogoh, Shunji Takaki, Chihiro Yamanaka, Motoji Ikeya, Eiji It ...専門分野: Magnetics resonances and relaxations in condensed matter; MÖssbauer effect.
1996 年 65 巻 3 号 p. 844-847
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThermoluminescence (TL) of coesite and stishovite has been measured after γ -ray irradiation at room temperature from 60Co. Analysis of the first TL peaks at 205°C indicates an activation energy, EI=1.20, eV and a pre-exponential frequency factor, s=1.3× 1012, Hz; the second peaks are at 240°C and at 255°C giving EII=1.27, eV and 1.32, eV for coesite and stishovite, respectively. ESR lines at g=2.002 with A⊥=46, mT and A//=59, mT show the same isochronal annealing behavior with the same parameters of thermal stability as those of the first TL peaks. Other ESR lines at g=2.002 with A⊥=50, mT and A//=53, mT are stable to high temperature. Atomic hydrogens, H0, in densified amorphous and in crystalline parts are responsible for the ESR signals and the release of trapped H0 leads to recombination with a hole center emitting the TL light.抄録全体を表示PDF形式でダウンロード (315K) -
Hitoshi Ohta, Masato Sumikawa, Mitsuhiro Motokawa, Hikomitsu Kikuchi, ...専門分野: Magnetics resonances and relaxations in condensed matter; MÖssbauer effect.
1996 年 65 巻 3 号 p. 848-852
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありHigh field ESR of Kagome antiferromagnets SrCrxGa12-xO19 have been observed in the submillimeter wave region from 1.8, K to 265, K. The concentration dependence was observed from x=0.6 to x=8.78, and all samples showed the decrease of the resonance field and broadening of linewidth as the temperature was decreased. As the linewidth is very broad at low temperature, for instance about 7, T at 4.2, K, the measurement using high frequency was essential. The results are discussed in connection with the peculiar magnetic behaviors of the system observed by other measurements.抄録全体を表示PDF形式でダウンロード (377K) -
Yoshihiro Ishibashi, Makoto Iwata専門分野: Dielectric properties and materials.
1996 年 65 巻 3 号 p. 853-857
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe spontaneous polarization and dielectric susceptibility of relaxors have been calculated for the second and the first order transition cases on the basis of the assumed Gaussian distribution of the transition temperatures. Dispersion of the susceptibility is obtained on the effective medium approximation. The obtained frequency dependences of the temperatures, where the susceptibility attains peak values, are found to agree qualitatively with the experimental results.抄録全体を表示PDF形式でダウンロード (260K) -
Susumu Matsuzaki, Shinya Basaki, Vyacheslav M. Yartsev専門分野: Optical properties and condensedmatter spectroscopy and other interactions of matter with particles and radiation.
1996 年 65 巻 3 号 p. 858-863
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThe pressure-induced neutral-ionic transition of TTF-DMDCNQI complex is analyzed by usinga simple dimer model with electron-intramolecular vibration coupling. The coupling is shown to be responsible for a sharp neutral-ionic phase transition and characteristic hysteresis in the degree of ionicity dependence upon pressure in this complex. Ground state charge distribution is calculated as a function of small-polaron binding energies and transfer integral between donor and acceptor sites.抄録全体を表示PDF形式でダウンロード (373K) -
Q. J. A. Khan, B. S. Bhatt, R. P. Jaju専門分野: Biophysics.
1996 年 65 巻 3 号 p. 864-867
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありThis paper complements the analysis of Khan, Bhatt and Jaju [1994]. They have studied non-switching and switching models with one predator and two prey species. In the former model predator feeds prey species indiscriminately while in the second model predator switches from a rare species towards the most abundant one. Using conversion rates of prey to predators as the bifurcation parameter it has been shown that Hopf bifurcation can occur in both models.抄録全体を表示PDF形式でダウンロード (231K) -
Ryuta Yagi, Hideto Kazawa, Takahide Yamaguchi, Shun–ichi Kobayas ...専門分野: Electronic transport in condensed matter.
1996 年 65 巻 3 号 p. 868-869
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありPDF形式でダウンロード (221K) -
Fuminao Shimizu, Shozo Sawada, Masaaki Takashige専門分野: Dielectric properties and materials.
1996 年 65 巻 3 号 p. 870-871
発行日: 1996/03/01
公開日: 1999/10/01
ジャーナル 認証ありPDF形式でダウンロード (169K)
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