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 共查询到17条相似文献,搜索用时 234 毫秒
1.
采用双子格模型和相干态表示,考虑磁-声子耦合作用和磁子间的相互作用,研究了序参量守恒的一维反铁磁分子晶体CeAs在外磁场存在下的非线性集体激发特性,并求了孤立子能量、质量和自旋的空间组态,给出在一维序参量守恒的反铁磁分子晶体CeAs中出现的非线性磁子局域特性。  相似文献   

2.
序参量守恒的反铁磁分子晶体的非线性集团激发   总被引:2,自引:2,他引:0  
采用双子格模型和相干态表示,考虑磁-声子耦合作用和磁子间的相互作用,研究了序参量守恒的一维反铁磁分子晶体CeAs在外磁场存在下的非线性集团激发特性,并求了孤立子能量,质量和自旋的空间组态,给出在一维序参量守恒的反铁磁分子晶体CeAs中出现的非线性磁子局域特性。  相似文献   

3.
考虑磁 -声子耦合作用和磁子间相互作用 ,采用双子格模型和相干态表示 ,研究了自旋S =1/2反铁磁体KCuF3 的非线性集体激发特性 ,求出了孤立子的能量和质量 ,并比较了磁性孤立子和局域性磁子激发能量。结果表明在一维反铁磁体KCuF3 中发现孤立子激发是可能。  相似文献   

4.
考虑磁-声子耦合作用和磁子间相互作用,采用双子格模型和相干态表示,研究了自旋S=1/2反铁磁体KCuF3的非线性集体激发特性,求出了孤立子的能量和质量,并比较了磁性孤立子和局域性磁子激发能量。结果表明在一维反铁磁体KCuF3中发现孤立子激发是可能。  相似文献   

5.
CuCl2·2N(C5D5)中的孤子激发   总被引:2,自引:0,他引:2  
采用双子格模型和相干态表示,考虑磁-声子耦合作用和磁子间的相互作用,研究了具有最近邻和次近邻相互作用的一维反铁磁分子晶体CuCl2·2N(C5D5)的非线性集体激发特性,分析了孤子的峰值、宽度、能量和有效质量的特点,结果表明CuCl2·2N(C5D5)中出现孤子激发是可能的。  相似文献   

6.
考虑了Amide-Ⅰ振子同肽群振动的光学声子相耦合,在该理论中研究了在蛋白质分子中的孤立子引起的红外吸收的反常红移和温度依赖关系。所得结果较好地吻合于实验值。从而也证实了蛋白质中确有孤立子激发的存在  相似文献   

7.
有机分子的Davydov孤立子激发   总被引:2,自引:0,他引:2  
本文从修正的Davydov、方程组出发,研究了α螺旋蛋白质分子中由于某种非线性相互作用所产生的集体激发,以及由此而产生的孤立子运动。最后我们给出了这种孤立子的特征  相似文献   

8.
文内研究了酰胺Ⅰ振动与其前后胺基酸残基分子间不对称耦合对蛋白质分子链上所激发孤立子的能量、动量等特性的影响。结果表明,无论是亚声速孤立子还是超声速孤立子都能被激发,并且这种非对称耦合致使亚声速孤立子的波形振幅、能量及动量增大,孤立子的形成能降低  相似文献   

9.
曹庆杰  张天德 《计算物理》1997,14(4):518-520
研究一类广义非线性Schrordinger方程的孤立子解及其性质,研究非线性参数变化时孤立子性态的变化规律,同时研究该系统的数值解法,得到了一类广义非线性Schroedinger方程差分格式的收敛性和稳定性的条件。  相似文献   

10.
有机蛋白质分子中存在有孤立子激发的实验证实   总被引:1,自引:0,他引:1  
庞小峰 《物理》1997,26(11):665-670
从实验上论证了有机蛋白质分子中是否存在孤立子激发有着重要的科学意义,它关系到20多年来提出和研究的生物能能量传递机制和理论的正确程度。文章综述了为证实其存在所作的红外吸收,拉曼散射,皮秒自由电子激光和泵-针实验等的结果。从这些结果可基本相信这类孤立子的存在,并是生物能量传递的载体。  相似文献   

11.
The formation of light envelope solitons has been experimentally observed under the pulsed excitation and propagation of radio-frequency spin-wave packets in a magnon crystal, a periodic magnetic film structure. The magnon crystal has been fabricated from a thin single-crystal yttrium iron garnet (YIG) film. The envelope solitons have been excited at frequencies corresponding to the edges of the Bragg-resonance-induced band gaps of the spin-wave spectrum of the magnon crystal. A theoretical explanation of the observed phenomenon has been proposed with the use of the numerical simulation of the formation of solitons based on the nonlinear Schrödinger equation.  相似文献   

12.
《Physics letters. A》2001,286(5):353-356
The spin wave excitation induced by infrared laser radiation in antiferromagnetic semiconductors is considered. By considering that several photons from the IR laser field can be involved in the electronic transition a kinetic equation for the magnon population is calculated from which the magnon excitation rate is calculated. It is found that under certain conditions the excitation rate may become greater than the magnon relaxation rate and the magnon system can reach instability. An application is made for the antiferromagnetic semiconductor EuTe.  相似文献   

13.
The existence and properties of intrinsic localized spin-wave modes in a ferromagnetic XXZ spin chain with Dzyaloshinsky-Moriya interaction are investigated analytically in the semiclassical limit. The model Hamiltonian is quantized by introducing the Dyson-Maleev transformation and the coherent state representation is chosen as the basic representation of the system. By making use of the method of multiple scales combined with a quasidiscreteness approximation, the equation of motion for the coherent-state amplitude is reduced to the nonlinear Schrödinger equation. It is shown that a bright intrinsic localized spin-wave mode whose eigenfrequency lies below the bottom of the magnon frequency band can exist in the ferromagnetic system. We also show that the system can produce a dark intrinsic localized spin-wave mode, i.e., nonpropagating kink, whose eigenfrequency is below the upper of the magnon frequency band. In addition, we find that the introduction of the Dzyaloshinsky-Moriya interaction changes wave numbers in the Brillouin-zone corresponding to the appearance of intrinsic localized spin-wave modes.  相似文献   

14.
《Physics letters. A》2006,353(5):427-430
In this Letter we discuss squeezing state of magnon in ferromagnet, which permits a reduction in the quantum fluctuation of the spin component to below the zero-point quantum noise level of coherent magnon states. We investigate the generation of squeezed magnon state through calculating the expectation values of spin component fluctuation. The mean field theory is introduced in dealing with the nonlinear interaction terms of Hamiltonian of magnon system.  相似文献   

15.
Ze Cheng 《Physica A》2010,389(24):5671-5676
We investigate a squeezed thermal spin state of nonlinear spin waves in Heisenberg ferromagnets. In this state, the magnon system possesses a new kind of quasiparticle, the dressed magnon, whose mass is a monotonically decreasing function of temperature. The noise of one spin component in the squeezed thermal spin state can be below the noise level in the vacuum state. The magnon system undergoes a first-order phase transition from the normal state to the squeezed thermal spin state. The critical temperature is much lower than the Curie temperature. A possible detection scheme based on a polarized neutron-scattering technique is suggested.  相似文献   

16.
成泰民  鲜于泽  江铁臣 《物理学报》2006,55(6):2941-2948
在二维复式正方Heisenberg铁磁系统的基础上建立了磁振子-声子相互作用模型. 利用松原格林函数理论研究了系统的磁激发,计算了布里渊区的主要对称点线上的磁振子色散曲线,比较了光频支声子与声频支声子对系统磁激发的影响以及各项参数的变化对磁振子软化的影响. 发现光频支声子-磁振子耦合对磁振子软化起主要作用,尤其是纵向光频支声子对磁振子软化起更大的作用,并且非磁性离子的光频支声子对磁振子软化的作用比磁性离子的光频支声子对磁振子软化的作用更显著.  相似文献   

17.
Recently, the photon–magnon coherent interaction based on the collective spins excitation in ferromagnetic materials has been achieved experimentally. Under the prospect, the magnons are proposed to store and process quantum information. Meanwhile, cavity-optomagnonics which describes the interaction between photons and magnons has been developing rapidly as an interesting topic of the cavity quantum electrodynamics. Here in this short review, we mainly introduce the recent theoretical and experimental progress in the field of optomagnetic coupling and optical manipulation based on cavity-optomagnonics. According to the frequency range of the electromagnetic field, cavity optomagnonics can be divided into microwave cavity optomagnonics and optical cavity optomagnonics, due to the different dynamics of the photon–magnon interaction. As the interaction between the electromagnetic field and the magnetic materials is enhanced in the cavity-optomagnonic system, it provides great significance to explore the nonlinear characteristics and quantum properties for different magnetic systems. More importantly, the electromagnetic response of optomagnonics covers the frequency range from gigahertz to terahertz which provides a broad frequency platform for the multi-mode controlling in quantum systems.  相似文献   

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