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 共查询到18条相似文献,搜索用时 46 毫秒
1.
二维情况下内部有质量费米子单圈图对Casimir力的贡献   总被引:1,自引:0,他引:1  
采用Feynman的路径积分量子化方法,计算出两个平行的、理想的金属线之间,在绝对零度下量子电磁场在有质量费米子单圈图近似下的Casimir效应.  相似文献   

2.
田文超  王林滨  贾建援 《物理学报》2010,59(2):1175-1179
针对微观黏附中出现的"突跳"问题,建立了正弦分布粗糙面黏附模型;基于Casimir效应推导出Casimir力表达式;基于Wigner-Seitz微观理论,推导出包含斥力项的Hamaker力表达式;经过对黏附过程数值仿真,发现存在两个"突跳"过程,曲线存在两个拐点,而非目前研究所得的单个"突跳"过程;仿真结果同相关实验对比,结果符合较好.从而为微纳器件检测和原子分子操纵等提供理论基础.  相似文献   

3.
研究以同轴不同半径柱面围成的导体柱环腔体中电磁场真空零点振动模式所给出的宏观量子效应.零点振动模式通过求解柱环空腔边界条件下无源的Maxwell方程组获得.得到了双柱面同心柱环中单位长度和单位面积的且是有限的真空能量,即Casimir能量.这有限的Casimir能量可以分解为独立而且收敛的三部分,它们分别来自内柱面、外柱面和柱环之中.对多柱面同心柱环,Casimir能量可分解为独立的(2n—1)部分(n为柱面数).柱环是类似于平行板的几何结构.但柱环所给出的Casimir能量和Casimir势能系数是随着 关键词: Casimir效应 柱环腔体 零点能 量子电动力学  相似文献   

4.
曾然  Yang Ya-Ping  刘树田 《物理学报》2008,57(8):4947-4952
研究了负折射率材料对产生Casimir排斥效应的影响. 两材料板间的Casimir排斥力的发生取决于两板以及其间媒质的电磁特性,通过理论与数值结果的分析研究给出电磁特性所影响排斥力的产生趋势. 对于由Drude-Lorentz型色散关系描述等效介电常数和磁导率的负折射率材料,调节各特征频率参数可实现Casimir排斥效应. 关键词: Casimir排斥力 负折射率材料 Drude-Lorentz型色散关系  相似文献   

5.
刘成周  张昌平 《物理学报》2007,56(4):1928-1937
在一般渐近平直的二维静态黑洞时空中,利用重正化能动张量的一般性质, 对位于两“平行板”间满足Dirichlet条件的无质量Dirac场的重正化能动张量的真空期待值进行了分析和计算, 得到了一般表达式.利用该表达式可以给出各种具体渐近平直二维静态黑洞时空中的相应Casimir力.对于重正化能动张量及Casimir力与真空态定义(包括Boulware 真空态、Hartle-Hawking真空态和Unrum真空态三种情况)、Hawking辐射和反常迹的关系分别进行了讨论,给出了相应的表达式和计算结果. 关键词: 能动张量 Casimir 效应 黑洞 真空态  相似文献   

6.
有限温度下的Casimir效应   总被引:1,自引:0,他引:1  
郑泰玉 《中国物理 C》1995,19(3):241-244
利用路径积分量子化方法,计算出两个平行的、理想的金属板之间,在有限温度下自由的量子电磁场和内部费米子单圈图对Casimir力的贡献.  相似文献   

7.
内部费米子单圈图对Casimir力的贡献   总被引:1,自引:0,他引:1  
郑泰玉 《中国物理 C》1990,14(9):796-801
本文利用路径积分量子化方法,计算了两个平行的、理想的金属板之间,内部费米子单圈图对Casimir力的贡献.其作用在单位面积金属板上的力为0.00025dyne/cm2.  相似文献   

8.
白占武 《物理学报》2004,53(8):2472-2477
在路径积分量子化框架下,利用复变函数论中的保角变换与Plana求和公式,计算了(2+1)维空间中两个非平行导线型边界下Maxwell-Chern-Simons场的Casimir效应.不引入任何截断参数,而得出有限的解析表达式. 关键词: Casimir效应 路径积分 保角变换 Plana求和公式  相似文献   

9.
曾然  许静平  羊亚平  刘树田 《物理学报》2007,56(11):6446-6450
研究了负折射率材料介质板间的Casimir效应.对于负折射率材料中由Drude-Lorentz型色散关系描述的介电常数和磁导率,色散曲线中负值频带的曲线结构由各色散吸收参数所决定,色散曲线负值频带宽度和负区域的深度等性质的变化影响了介质材料板的反射特性,进而对两材料板间的Casimir效应强弱起着重要的作用.  相似文献   

10.
在金属板与电介质材料板基底间插入色散特异材料板形成三明治结构,并对其Casimir作用力进行了研究.基于Casimir-Lifshitz理论,通过麦克斯韦应力张量计算了真空涨落的辐射压,并对三明治结构利用电磁模式传输矩阵方法进行了数值计算分析.计算结果表明,原本两板结构中存在的Casimir吸引力,在插入特异材料板后的三明治结构中将转变为斥力,从而使轻薄的金属板产生量子悬浮效应。讨论了特异材料板的色散电磁响应特性以及电介质板基底的影响,结果表明特异材料磁等离子频率越大、磁共振频率越小以及电介质板基底的介电常数越小时,三明治结构中获得的斥力越大.此外,板间距增加到一定范围时,三明治结构中将出现Casimir平衡回复力.特异材料填充因子越小、三明治结构中层距和层厚越大时,三明治结构间的回复力会出现在较长距的位置.三明治结构中的量子悬浮效应与平衡回复力可保证微纳米机械系统稳定性,展现出基于真空辐射压的应用前景.  相似文献   

11.
程红波 《理论物理通讯》2010,53(6):1125-1132
The Casimir effect of a piston for massless scalar fields which satisfy Dirichlet boundary conditions in the context of five-dimensional Randall- Sundrum models is studied. In these scenarios we derive and calculate the expression for the Casimir force on the piston. We also discuss the Casimir force in the limit that one outer plate is moved to the remote place to show that the nature of the reduced force between the parallel plates left. In the Randall~undrum model involving two branes the two plates attract each other when they locate very closely, but the reduced Casimir force turns to be repulsive as the plates separation is not extremely tiny, which is against the experimental phenomena, meaning that the RSI model can not be acceptable. In the case of one brane model the shape of the reduced Casimir force is similar to that of the standard two-parallel-system in the four-dimensional fiat spacetimes while the sign of force remains negative.  相似文献   

12.
We calculate the Casimir force between a perfect reflective wall and a semitransparent wall in the laser cavity. Using the Fox-Li quasimode theory to describe the electromagnetic field in the laser cavity, the vacuum energy and the Casimir force are calculated. We compare our results to the force in the ideal situation and find it smaller in the dissipative cavity. We also find that the Casimir force decreases with the increase of the wall-wall distance and the decay rate of the quasimodes in the laser cavity.  相似文献   

13.
The Casimir force between a perfectly conducting wall and a dielectric wall in a cavity comprising a transparent dielectric with output coupling is investigated. By using full quantum theory, we obtain the analysis expression of the force, which shows that the interaction of the two walls in this system is always repulsive. And the value of the Casimir force varies with the field amplitude reflectivity and the cavity size.  相似文献   

14.
Anushree Roy  U Mohideen 《Pramana》2001,56(2-3):239-243
Here we review our work on measurement of the Casimir force between a large aluminum coated a sphere and flat plate using an atomic force microscope. The average statistical precision is 1% of the force measured at the closest separation. We have also shown nontrival boundary dependence of the Casimir force.  相似文献   

15.
The Casimir force between a perfectly conducting wall and a dielectric wall in a cavity comprising a transparent dielectric with output coupling is investigated. By using full quantum theory, we obtain the analysis expression of the force, which shows that the interaction of the two walls in this system is always repulsive. And the value of the Casimir force varies with the field amplitude reflectivity and the cavity size.  相似文献   

16.
We calculate the Casimir force at a finite cut-off A by summing the forces induced by the all fluctuation modes. We show that the Casimir force is independent of the cut-off function in the limit L∧ → ∞. There is a correction in the order of (L∧)^-2, when L∧ is finite and large. This correction becomes remarkable when L is comparable with the microscopic length scale ∧^-1. It has been demonstrated that the Casimir force at a finite cut-off should be defined by summing forces of all fluctuation modes, instead of the derivative of Casimir energy with respect to L where an additional derivative of the cut-off function has been introduced.  相似文献   

17.
We calculate the Casimir force at a finite cut-off Λ by summing the forces induced by the all fluctuation modes. We show that the Casimir force is independent of the cut-off function in the limit LΛ → ∞. There is a correction in the order of (LΛ)-2, when LΛ is finite and large. This correction becomes remarkable when L is comparable with the microscopic length scale Λ-1. It has been demonstrated that the Casimir force at a finite cut-off should be defined by summing forces of all fluctuation modes, instead of the derivative of Casimir energy with respect to L where an additional derivative of the cut-off function has been introduced.  相似文献   

18.
The Casimir stress on a cylindrical shell in the de Sitter background for a massless scalar field satisfying Dirichlet boundary conditions on the cylinder is calculated. The metric is written in conformally flat form to make maximal use of the Minkowski space calculations. In the framework of a toy model, we have considered the quantum vacuum effect in the evolution of a domain wall between a cylindrical or in fact circle region around the z axis in which vacuum is in and the remaining part of space where vacuum is out .  相似文献   

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