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Heat Conductivity in a Two-Dimensional Finite-Size Spin System with Dzyaloshinskii-Moriya Interactions
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Heat conductivity is studied by direct numerical simulations in a two-dimensional model with chiral Dzyaloshinskii-Moriya (DM) spin superexchange interactions for various DM strengths and finite sizes. We find that when temperature is not too low, the thermal conductivity can be well described in the semi-classical spin wave picture, and connections of thermal conductivity with the specific heat and the dynamic relaxation time are verified to be suitable. In particular, the transition arising in Sr14-xCaxCu24O41 is related to a magnetic spin glass and qualitatively understood as a kind of Kosterlitz-Thouless transitions. It is shown that the critical temperature is linearly dependent on the spin-spin interactions for the relevant strong DM strength. 相似文献
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基于推广的电-声相互作用模型,考虑到电子的强关联作用,提出了电子算符的玻戈留玻夫近似,导出了声子在电子场中受到的有效作用;证明了波矢相反的纵声子通过交换虚电子能产生一个有效的吸引力,从而构成带有一个电子的声子对。在适当的声子数密度下,形成稳定的费密高温超导态。 相似文献
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易林 《华中科技大学学报(自然科学版)》1993,(2)
利用推广的自洽迭代递归方法,精确求解了具有s-d交换相互作用系统的磁场顶角函数;计算了Kondo电导张量.发现,经过顶角函数的高级修正后,电导张量缩小到无高级修正值的1/(1+h~2). 相似文献
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基于推广的电-声相互作用模型,考虑到电子的强关联作用,提出了电子算符的玻戈留玻夫近似,导出了声子在电子场中受到的有效作用;证明了波矢相反的纵声子通过交换虚电子能产生一个有效的吸引力,从而构成带有一个电子的声子对。在适当的声子数密度下,形成稳定的费密高温超导态。 相似文献
46.
Using the F-expansion method we present analytical matter-wave solutions to Bose-Einstein condensates with two- and three-body interactions through the generalized three-dimensional Gross-Pitaevskii equation with time- dependent coefficients, for the periodically time-varying interactions and quadratic potential strength. Such solutions exist under certain conditions, and impose constraints on the functions describing potential strength, nonlinearities, and gain (loss). Various shapes of analytical matter-wave solutions which have important applications of physical interest are s~udied in details. 相似文献
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Universal Quantum Fluctuations and Crossover Phenomena in Tunnelling Through Small Coulomb Islands
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Tunnelling through small Coulomb islands is studied in the intermediate coupling regime based on a generalized multi-level Anderson-Wolff model.It is shown that conductance and magnetization as a function of voltage exhibit a type of universal quantum fluctuation.We predict new crossover from the Coulomb blockade oscillations to the universal conductance fluctuations,and the Coulomb blockade oscillation assisted Kondo peaks. 相似文献
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用分水器分水与苯或甲苯恒沸脱水相结合的方法,以浓盐酸或对甲苯磺酸作催化剂,系统地研究了乙酰丙酮与芳香胺单Schiff碱的合成;制备出六个相应的Schiff碱,产率高达60%~87%. 相似文献
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通过对攀枝花城市气候优势、植物资源优势、社会经济状况、城市发展前景与现有建设基础的分析,结合对国内相关城市植物园的特色研究,得出在攀枝花建设富有地方特色的综合性植物园是现实可行。其特色应突出攀枝花南亚热带干热河谷地带植物的地方特色。在植物品种上以苏铁等攀西特色植物为主;在功能上力求实现其科研、科普,旅游和园林绿化生产经营的综合性。 相似文献