排序方式: 共有46条查询结果,搜索用时 15 毫秒
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Orlova EE Hovenier JN Klaassen TO Kasalynas I Adam AJ Gao JR Klapwijk TM Williams BS Kumar S Hu Q Reno JL 《Physical review letters》2006,96(17):173904
An antenna model is proposed for long (L > A) lasers with subwavelength cross sections (wire lasers). It is shown that the far-field pattern of the wire lasers is determined by the ratio of the wavelength to the length. The radiation of the wire laser is predicted to be concentrated in a narrow beam theta approximately radical(2lambda/L) for laser modes where the longitudinal phase velocity is in synchronism with the velocity of light in air. Experimental results obtained using a terahertz quantum cascade wire laser are in agreement with the model. 相似文献
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Anissimova S Venkatesan A Shashkin AA Sakr MR Kravchenko SV Klapwijk TM 《Physical review letters》2006,96(4):046409
We measure the thermodynamic magnetization of a low-disordered, strongly correlated two-dimensional electron system in silicon in perpendicular magnetic fields. A new, parameter-free method is used to directly determine the spectrum characteristics (Landé g factor and the cyclotron mass) when the Fermi level lies outside the spectral gaps and the interlevel interactions between quasiparticles are avoided. Intralevel interactions are found to strongly modify the magnetization, without affecting the determined g* and m*. 相似文献
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Barends R Baselmans JJ Yates SJ Gao JR Hovenier JN Klapwijk TM 《Physical review letters》2008,100(25):257002
The quasiparticle relaxation time in superconducting films has been measured as a function of temperature using the response of the complex conductivity to photon flux. For tantalum and aluminum, chosen for their difference in electron-phonon coupling strength, we find that at high temperatures the relaxation time increases with decreasing temperature, as expected for electron-phonon interaction. At low temperatures we find in both superconducting materials a saturation of the relaxation time, suggesting the presence of a second relaxation channel not due to electron-phonon interaction. 相似文献
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Studies of low-frequency resistance noise show that the glassy freezing of the two-dimensional (2D) electron system in the vicinity of the metal-insulator transition occurs in all Si inversion layers. The size of the metallic glass phase, which separates the 2D metal and the (glassy) insulator, depends strongly on disorder, becoming extremely small in high-mobility samples. The behavior of the second spectrum, an important fourth-order noise statistic, indicates the presence of long-range correlations between fluctuators in the glassy phase, consistent with the hierarchical picture of glassy dynamics. 相似文献
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Vitkalov SA Zheng H Mertes KM Sarachik MP Klapwijk TM 《Physical review letters》2000,84(10):2164-2167
We show that the smectic layer orientation in side-chain liquid-crystalline polymers depends on the molecular weight and the shear rate. Parallel orientation is obtained with the low molecular weight polymer and reveals a shear induced decrease of the smectic layer thickness. In contrast with usual liquid crystals, the shear torque acts at the mesogen scale through an efficient coupling between the polymer main chain and the mesogens resulting in a smectic- A-smectic- C transition. 相似文献
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We analyze theoretically adiabatic quantum pumping through a normal conductor that couples the normal regions of two superconductor - normal-metal - superconductor Josephson junctions. By using the phases of the superconducting order parameter in the superconducting contacts as pumping parameters, we demonstrate that a nonzero pumped charge can flow through the device. The device exploits the evolution of the superconducting phases due to the ac Josephson effect, and can therefore be operated at very high frequency, resulting in a pumped current as large as a few nanoamperes. The experimental relevance of our calculations is discussed. 相似文献
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M. P. Sarachik D. Simonian K. M. Mertes S. V. Kravchenko T. M. Klapwijk 《Physica B: Condensed Matter》2000,280(1-4):301-302
Hall coefficient measurements are reported for the two-dimensional electron system in silicon MOSFETs for densities throughout the metallic phase and very near the transition to insulating behavior. 相似文献
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We have experimentally studied the spin-induced time reversal symmetry (TRS) breaking as a function of the relative strength of the Zeeman energy (E(Z)) and the Rashba spin-orbit interaction energy (E(SOI)), in InGaAs-based 2D electron gases. We find that the TRS breaking, and hence the associated dephasing time tau(phi)(B), saturates when E(Z) becomes comparable to E(SOI). Moreover, we show that the spin-induced TRS breaking mechanism is a universal function of the ratio E(Z)/E(SOI), within the experimental accuracy. 相似文献