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91.
Masanori Yamanaka Shinsuke Honjo Yasuhiro Hatsugai Mahito Kohmoto 《Journal of statistical physics》1996,84(5-6):1133-1208
We investigate one-dimensional strongly correlated electron models which have the resonating-valence-bond state as the exact ground state. The correlation functions are evaluated exactly using the transfer matrix method for the geometric representations of the valence-bond states. In this method, we only treat matrices with small dimensions. This enables us to give analytical results. It is shown that the correlation functions decay exponentially with distance. The result suggests that there is a finite excitation gap, and that the ground state is insulating. Since the corresponding noninteracting systems may be insulating or metallic, we can say that the gap originates from strong correlation. The persistent currents of the present models are also investigated and found to be exactly vanishing. 相似文献
92.
Precise temperature and polarization dependences of Raman spectra have been investigated for fully oxygenated twin-free YBa2Cu3O7 single crystals. We have found a striking superconductivity-induced x−y anisotropy in the temperature behavior of the 340 cm−1 line: the magnitudes of the softening and broadening are quite different in the xx-and yy-polarizations. This anisotropy suggests a contribution of the CuO-chain superconductivity with a pairing symmetry different
from that for the CuO2 plane, or indicates that the superconducting gap amplitudes are different in the k
x and k
y directions. The d+s gap symmetry is the only realistic symmetry in the case of Δx≠Δy.
Fiz. Tverd. Tela (St. Petersburg) 40, 403–412 (March 1998)
Published in English in the original Russian journal. Reproduced here with stylistic changes by the Translation Editor. 相似文献
93.
We analyze the effects of inelastic scattering on the tunneling time theoretically, using generalized Nelson’s quantum mechanics.
This generalization enables us to describe quantum system with channel couplings and optical potential in a real time stochastic
approach, which seems to give us a new insight into quantum mechanics beyond Copenhagen interpretation 相似文献
94.
95.
96.
Takesi Hayakawa 《Annals of the Institute of Statistical Mathematics》1977,29(1):359-378
Summary Asymptotic expansion of the distribution of the likelihood ratio criterion (LRC) for testing a composite hypothesis is derived
under null hypothesis and a correction factor ρ which makes the term of order 1/n in the asymptotic expansion of the distribution of it vanish is obtained. The problem is extended to the case of a general
composite hypothesis and of Pitman's local alternatives. The asymptotic distribution of LRC for a simple hypothesis is studied
under a fixed alternative.
The Institute of Statistical Mathematics 相似文献
97.
98.
Field quenching phenomena were observed in the photo-induced changes in dark current—voltage and dark low frequency capacitance-voltage characteristics of hydrogenated amorphous silicon (a-Si:H) diodes. The photo-induced changes in photoconductivity of undoped a-Si:H measured in coplanar type samples also depended on the externally applied electric field. The mechanisms of the field quenching were discussed referring to trapping and/or recombination of photogenerated carriers in a-Si:H. 相似文献
99.
Yoshiaki Tsunawaki Nobuhisa Ohigashi Kunioki Mima Shin-ichiro Kurama Kazuo Imasaki Masayuki Fujita Chiyoe Yamanaka Sadao Nakai 《International Journal of Infrared and Millimeter Waves》1995,16(1):317-325
A three dimensional simulation software system developed to estimate a free electron laser (FEL) gain has been applied to FEL using a standard plane polarized wiggler and an alternately shifted magnet wiggler. It is seen for the latter wiggler that a large filling factor could be selected and each maximum gain corresponding to each orbit of electron beam concentrates at a certain frequency region of FEL radiation. It is, therefore, implied that a proper shift between the adjacent magnets in the wiggler produces the improvement of the FEL gain. 相似文献
100.
K. Ruwali A. Yamanaka K. Hosoyama 《Physica C: Superconductivity and its Applications》2010,470(13-14):553-557
An experiment was carried out to study the motion of superconducting wire under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as tension to the superconducting wire, current ramp rate, and the use of different insulating materials at the interface of the superconducting wire. We were able to examine in detail the structure of the voltage spikes caused by sudden wire motion. The velocity of the wire motion, distance moved by the wire, and energy dissipated during wire motion are estimated. 相似文献