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1.
强磁场中氢原子能级的另一种绝热变分计算   总被引:2,自引:0,他引:2       下载免费PDF全文
石玉珠  李丽萍  李毓成 《物理学报》1998,47(8):1241-1247
采用绝热近似和变分原理,引入描述Coulomb作用的等效模型势,给出绝热变分方程,计算了均匀强磁场(1≤β≤2000)中氢原子的基态和几个较低激发态的能级,并与绝热近似方法和公认为最精确的类多组态Hartree-Fock方法的结果进行了比较,给出的基矢比Landau基矢具有更好的收敛性. 关键词:  相似文献   

2.
S2分子X^3—Σ^—g和B^3Σ^—u态的势能函数和振动光谱特征   总被引:12,自引:4,他引:8  
应用实验光谱数据,导出了S2的基态分子X3Σ-g和激发态B3Σ-u的MurelSorbie势能函数,并用QCISD(T)/6-311G方法对基态进行了计算,结果在吸引支出现了回避相交而产生了一个浅平极大,其他部位与实验结果符合甚好。计算了B3Σ-u和X3Σ-g态的全部振动能级,以及激发态(B3Σ-u)振动能级≤9和基态(X3Σ-g)振动能级≤30之间的Deslandres表。给出了B3Σ-u-X3Σ-g跃迁Condon抛物线,各振动态的计算结果与实验值很好符合。  相似文献   

3.
李华钟 《物理学进展》2011,28(4):396-400
本文引介绝热量子计算理论评述量子绝热定理最新的应用。基于量子绝热方法在最新的前沿领域量子计算中建立量子绝热算法。我们引介"局域量子绝热",并考虑了这一局域绝热概念对量子算法的可能应用。  相似文献   

4.
绝热量子计算理论引介   总被引:2,自引:0,他引:2  
本文引介绝热量子计算理论评述量子绝热定理最新的应用.基于量子绝热方法在最新的前沿领域量子计算中建立量子绝热算法.我们引介"局域量子绝热",并考虑了这一局域绝热概念对量子算法的可能应用.  相似文献   

5.
LNG球形贮罐绝热计算   总被引:1,自引:1,他引:0  
分析了贮罐绝热体的传热规律,并建立了模型。通过近似理论计算得到了通过绝热体的传热量;利用计算软件对绝热体内传热过程进行了有限元计算,获得了通过贮罐绝热体的传热量以及绝热体内温度场的分布。以传热量为基准,将近似理论计算与有限元计算结果进行比较,表明有限元计算结果更为准确。  相似文献   

6.
采用绝热变分近似方法,计算了均匀强磁场(0.5≤β≤1000)中H+2的Δu,Φg,Γu,Hg态(无外磁场或外磁场较弱时为反键态)的能级及原子核间的平衡距离,并与前人的结果进行了比较。  相似文献   

7.
采用绝热变分近似方法 ,计算了均匀强磁场 (0 .5≤β≤ 10 0 0 )中H 2 的Δu,Φg,Γu,Hg 态 (无外磁场或外磁场较弱时为反键态 )的能级及原子核间的平衡距离 ,并与前人的结果进行了比较。  相似文献   

8.
采用绝热离分近似方法,计算最均匀强磁场(0.5≤β≤1000)中H2^+的△μ,Φg,Гu,Hg态(无外磁场或外磁场较弱时为反键)的能级及原子核间的平衡距离,并与前人的结果进行了比较。  相似文献   

9.
电子束的绝热展开   总被引:1,自引:0,他引:1  
考虑空间电荷效应,用数值方法模拟计算了电子束绝热展开过程.当初始磁感应强度与最终磁感应强度之比为K时,电子束横向温度由初始值Ti降低Ti/K.研究了不同能量、不同流强的电子束达到预期的绝热展开倍数所需的最低磁感应强度.  相似文献   

10.
板条侧面绝热技术研究   总被引:2,自引:2,他引:0       下载免费PDF全文
 分析了当侧面绝热不彻底时所带来的侧向温度梯度对板条光程畸变造成的影响,提出采用吸收材料吸收板条的自发辐射,控制吸收材料的温升使之与板条中心的平均温度相同的方法来实现板条侧面绝热,并给出了“隔热层+吸收层+铜热沉”的绝热结构的设计方法。板条热透镜效应实验结果表明,在500Hz重复频率下,未装绝热结构的板条热焦距为0.78m,而装有绝热结构的板条的热焦距为1.93m,热聚焦大为改善。  相似文献   

11.
文章首先概述了近年国际文献中关于量子绝热近似和绝热条件的不自洽性的研究.叙述了文献中关于绝热近似不自洽性的论证和争论.然后引入文章作者的观点,从不同于国外文献的角度出发指出应当正确地理解瞬时本征函数的相位问题,从这个相位的正确处理,得出结论:(1)MS不自洽的存在,不因计及几何相位而消除;(2)量子几何相位不自洽是不存在;(3)现时的标准的绝热近似条件不是充分条件.  相似文献   

12.
李华钟 《物理》2007,36(1):26-31
文章首先概述了近年国际文献中关于量子绝热近似和绝热条件的不自洽性的研究.叙述了文献中关于绝热近似不自洽性的论证和争论.然后引入文章作者的观点,从不同于国外文献的角度出发指出应当正确地理解瞬时本征函数的相位问题,从这个相位的正确处理,得出结论:(1)MS不自洽的存在,不因计及几何相位而消除;(2)量子几何相位不自洽是不存在;(3)现时的标准的绝热近似条件不是充分条件.  相似文献   

13.
The concept of the adiabatic approximation is introduced from a few new standpoints, and the conditions are refined under which we can assume that the total energy of an electronic-vibrational (vibronic) state is the sum of the energies of the “electronic” and the “nuclear” problems and the wave function is represented as the product of the corresponding functions. An expression exactly corresponding to such an approximation is considered for the optical transition matrix element, and its individual terms are analyzed for any change in the geometric structure of the molecule upon optical excitation. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 290–293, May–June, 2006.  相似文献   

14.
In this paper,we derive an upper bound for the adiabatic approximation error,which is the distance between the exact solution to a Schr dinger equation and the adiabatic approximation solution.As an application,we obtain an upper bound for 1 minus the fidelity of the exact solution and the adiabatic approximation solution to a Schrdinger equation.  相似文献   

15.
For a given Hermitian Hamiltonian H(s)(s∈[0,1])with eigenvalues Ek(s)and the corresponding eigenstates|Ek(s)(1 k N),adiabatic evolution described by the dilated Hamiltonian HT(t):=H(t/T)(t∈[0,T])starting from any fixed eigenstate|En(0)is discussed in this paper.Under the gap-condition that|Ek(s)-En(s)|λ0 for all s∈[0,1]and all k n,computable upper bounds for the adiabatic approximation errors between the exact solution|ψT(t)and the adiabatic approximation solution|ψadi T(t)to the Schr¨odinger equation i|˙ψT(t)=HT(t)|ψT(t)with the initial condition|ψT(0)=|En(0)are given in terms of fidelity and distance,respectively.As an application,it is proved that when the total evolving time T goes to infinity,|ψT(t)-|ψadi T(t)converges uniformly to zero,which implies that|ψT(t)≈|ψadi T(t)for all t∈[0,T]provided that T is large enough.  相似文献   

16.
介绍了求解慢变体系的薛定谔方程的高级浸渐近似方法,并通过理论分析和数值计算讨论了这一方法的适用性。  相似文献   

17.
We investigate the dynamics of two qubits coupled with a quantum oscillator by using the adiabatic approximation method. We take account of the interaction between the qubits and show how the entanglement is affected by the interaction parameter. The most interesting result is that we can prolong the entanglement time or improve the entanglement degree by using an appropriate interaction parameter. As the generation and preservation of entanglement of qubits are crucial for quantum information processing, our research will be useful.  相似文献   

18.
董锟 《中国物理 B》2016,25(12):124202-124202
Using adiabatic approximation, a two arbitrary qubits Rabi model has been studied in ultra-strong coupling. The analytical expressions of the eigenvalues and the eigenvalues are obtained. They are in accordance with the numerical determined results. The dynamical behavior of the system and the evolution of entanglement have also been discussed. The collapse and revival phenomena has garnered particular attention. The influence of inconsistent coupling strength on them is studied. These results will be applied in quantum information processing.  相似文献   

19.
蒋占峰  李润东  刘伍明 《物理》2005,34(4):274-278
自旋电子学是近年来凝聚态物理研究中的一个热点.文章介绍了量子自旋流的概念,着重论述了一种新近出现的理论,其预言在一大类空穴掺杂的半导体中存在自旋流.计算了自旋流的大小,并论述了它在室温下无耗散的特性,最后给出了两种在实验中探测自旋流的方案.  相似文献   

20.
In this paper, we present a quantitative sufficient condition for adiabatic approximation in PT-symmetric quantum mechanics, which yields that a state of the PT-symmetric quantum system at any time will remain approximately in the m-th eigenstate up to a multiplicative phase factor whenever it is initially in the m-th eigenstate of the Hamiltonian. In addition, we estimate the approximation errors by the distance and the fidelity between the exact solution and the adiabatic approximate solution to the time evolution equation, respectively.  相似文献   

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