排序方式: 共有12条查询结果,搜索用时 15 毫秒
1.
A. B. Novikov B. V. Novikov R. B. Yuferov H. Röppischer N. Stein A. V. Sel'kin 《JETP Letters》1996,64(1):42-46
The low-temperature (T=80 K) excitonic light reflection spectra of CdS crystals in the electric field of a Schottky barrier are investigated. An
anomalous Stark shift of the hydrogen-like excitonic state in the preionization limit is recorded for the first time. The
distribution of the subbarrier electric field is determined from an analysis of the spectra performed on the basis of the
theory of nonlocal dielectric response in a spatially inhomogeneous medium.
Pis'ma Zh. éksp. Teor. Fiz. 64, No. 1, 38–42 (10 July 1996) 相似文献
2.
We consider solvable invariant subgroups of a finite group with bounded primary indices of maximal subgroups. We establish that an invariant subgroup of this type belongs to the product of classical formations and investigate its dispersibility. 相似文献
3.
V. G. Golubev A. V. Medvedev A. B. Pevtsov A. V. Sel'kin N. A. Feoktistov 《Physics of the Solid State》1999,41(1):137-142
Photoluminescence spectra of thin hydrogenated-silicon films having mixed amorphous-nanocrystalline phase composition have
been studied. Fabry-Perot interference was found to affect strongly the shape of the spectra. An analysis of the spectra made
with inclusion of interference corrections shows that only one emission band forms in the 0.6–1.0 μm region due to carrier
recombination at centers of the same type.
Fiz. Tverd. Tela (St. Petersburg) 41, 153–158 (January 1999) 相似文献
4.
R Nirmala V Sankaranarayanan K Sethupathi AV Morozkin T Geethakumary Y Hariharan 《Pramana》2002,58(5-6):1101-1104
New R
2Ti3Ge4 (R=Dy, Ho and Er) intermetallic compounds have been synthesized and characterized by X-ray diffraction and low temperature ac
magnetic susceptibility, electrical resistivity and thermoelectric power measurements were carried out. The compounds crystallize
in the parent, Sm5Ge4-type orthorhombic structure (space group Pnma) and lanthanide contraction is observed as one moves along the rare-earth series.
The changeover from paramagnetic to antiferromagnetic phase happens at low temperatures and the ordering temperature scales
with the de Gennes factor. The electrical resistivity is metallic with a negative curvature above 100 K. Thermopower displays
a weak maximum at temperatures less than 50 K signifying the possible phonon and magnon drag effects. 相似文献
5.
6.
7.
We describe minimal hereditary -local non--formations, where is a formation of the classical type. 相似文献
8.
Mazurenko DA Kerst R Dijkhuis JI Akimov AV Golubev VG Kurdyukov DA Pevtsov AB Sel'kin AV 《Physical review letters》2003,91(21):213903
We present the first experimental investigation of ultrafast optical switching in a three-dimensional photonic crystal made of a Si-opal composite. Ultrafast (30 fs) changes in reflectivity around the photonic stop band up to 1% were measured for moderate pump power (70 microJ/cm(2)). Short-lived photoexcited carriers in silicon induce changes in the dielectric constant of Si and diminish the constructive interference inside the photonic crystal. The results are analyzed within a model based on a two-band mixing formalism. 相似文献
9.
Baryshev AV Khanikaev AB Inoue M Lim PB Sel'kin AV Yushin G Limonov MF 《Physical review letters》2007,99(6):063906
We demonstrate that, in contrast with the well-studied photonic crystals consisting of two homogeneous components, photonic crystals comprised of inhomogeneous or multiple (three or more) components may bring new opportunities to photonics due to the discovered quasiperiodic resonant behavior of their (hkl) stop bands as a function of the reciprocal lattice vector. A resonant stop band cannot be switched off for any permittivity of structural components. Tuning the permittivity or structural parameters allows the selective on-off switching of nonresonant (hkl) stop bands. This independent manipulation of light at different Bragg wavelengths provides a new degree of freedom to design selective optical switches and waveguides. Transmission experiments performed on synthetic opals confirmed the theoretical predictions. 相似文献
10.
Resonant ultrasound spectroscopy was used to measure the elastic constants of bcc Ta0.33V0.67 over the temperature range 3.5–300?K; the results were compared to earlier measurements on C15 TaV2. The temperature dependence of the polycrystalline shear modulus is completely different in the two phases; that of the bcc phase decreases with temperature whereas that of the C15 phases increases in an anomalous fashion. This difference is consistent with a model involving doubly-degenerate levels at the X point of the Brillouin zone in the C15 phase with the Fermi level lying near the doubly degenerate level. This model accounted for the unusual behaviour of the C15 phase. Debye temperatures were determined from the ultrasonic measurements: 295?K for the C15 phase and 315?K for the bcc phase. 相似文献