排序方式: 共有50条查询结果,搜索用时 46 毫秒
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Irina Khromova Petr Kuel Igal Brener John L. Reno U‐Chan Chung Seu Catherine Elissalde Mario Maglione Patrick Mounaix Oleg Mitrofanov 《Laser \u0026amp; Photonics Reviews》2016,10(4):681-687
Monocrystalline titanium dioxide (TiO2) micro‐spheres support two orthogonal magnetic dipole modes at terahertz (THz) frequencies due to strong dielectric anisotropy. For the first time, we experimentally detected the splitting of the first Mie mode in spheres of radii m through near‐field time‐domain THz spectroscopy. By fitting the Fano lineshape model to the experimentally obtained spectra of the electric field detected by the sub‐wavelength aperture probe, we found that the magnetic dipole resonances in TiO2 spheres have narrow linewidths of only tens of gigahertz. Anisotropic TiO2 micro‐resonators can be used to enhance the interplay of magnetic and electric dipole resonances in the emerging THz all‐dielectric metamaterial technology.
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The microwave induced magnetoresistance in a GaAs/AlGaAs heterostructure was studied at temperatures below 1 K and frequencies in the range of 150-400 GHz. A distinct node in the Shubnikov-de Haas oscillations, induced by the microwave radiation, is clearly observed. The node position coincides with the position of the cyclotron resonance on the carriers with effective mass (0.068±0.005)m0. 相似文献
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Bowers CR Caldwell JD Gusev G Kovalev AE Olshanetsky E Reno JL Simmons JA Vitkalov SA 《Solid state nuclear magnetic resonance》2006,29(1-3):52-65
Nuclear magnetic resonance is detected via the in-plane conductivity of a two-dimensional electron system at unity Landau level filling factor in the regime of the quantum Hall effect in narrow and wide quantum wells. The NMR is spatially selective to nuclei with a coupling to electrons in the current carrying edge states at the perimeter of the 2DES. Interpretation of the electron-nuclear double resonance signals is facilitated by numerical simulations. A new RF swept method for conductivity-detected NMR is introduced which offers more efficient signal averaging. The method is applied to the study of electric quadrupole interactions, weakly allowed overtone transitions, and evaluation of the extent of electron wave function delocalization in the wide quantum well. 相似文献
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Mixtures of magnetite and zinc powders were milled for up to 540 minutes and the development of the system was followed using X-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. The process takes place in two overlapping steps. During the first hour of milling, a nonmagnetic intermediate mixed oxide phase forms which decomposes into ZnO and Fe upon further milling. The freshly formed iron particles are supersaturated with Zn. 相似文献
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We report the demonstration of distributed-feedback terahertz quantum-cascade lasers based on a first-order grating fabricated via a lateral corrugation in a double-sided metal ridge waveguide. The phase of the facet reflection was precisely set by lithographically defined facets by dry etching. Single-mode emission was observed at low to moderate injection currents, although multimode emission was observed far beyond threshold owing to spatial hole burning. Finite-element simulations were used to calculate the modal and threshold characteristics for these devices, with results in good agreement with experiments. 相似文献