We conduct a theoretical study on the properties of a bound polaron in a quantum well under an electric field using linear combination operator and unitary transformation methods, which are valid in the whole range of...We conduct a theoretical study on the properties of a bound polaron in a quantum well under an electric field using linear combination operator and unitary transformation methods, which are valid in the whole range of electron-LO phonon coupling. The changing relations between the ground-state energy of the bound polaron in the quantum well and the Coulomb bound potential, the electric field strength, and the well width are derived. The numerical results show that the ground-state energy increases with the increase of the electric field strength and the Coulomb bound potential and decreases as the well width increases.展开更多
A systematic theory on the appropriate spin operators for the relativistic states is developed. For a massive relativistic particle with arbitrary nonzero spin, the spin operator should be replaced with the relativist...A systematic theory on the appropriate spin operators for the relativistic states is developed. For a massive relativistic particle with arbitrary nonzero spin, the spin operator should be replaced with the relativistic one, which is called in this paper as moving spin. Further the concept of moving spin is discussed in the quantum field theory. A new operator, field quanta spin is defined and in terms of the generators of Poincaré group the moving spin of field system is constructed. It is shown that, in virtue of the two operators, problems in quantum field concerned spin can be neatly settled.展开更多
In the coherent thermal state representation we introduce thermal Wigner operator and find that it is'squeezed' under the thermal transformation. The thermal Wigner operator provides us with a new direct and n...In the coherent thermal state representation we introduce thermal Wigner operator and find that it is'squeezed' under the thermal transformation. The thermal Wigner operator provides us with a new direct and neatapproach for deriving Wigner functions of thermal states.展开更多
By virtue of the parabose squeezed operator, propagator of a parabose parametric amplifier, explicit forms of parabose squeezed number states and normalization factors of excitation states on a parabose squeezed vacuu...By virtue of the parabose squeezed operator, propagator of a parabose parametric amplifier, explicit forms of parabose squeezed number states and normalization factors of excitation states on a parabose squeezed vacuum state are calculated, which generalize the relevant results from ordinary Bose statistics to the parabose case.展开更多
The critical behaviors of a mixed spin-1/2 and spin-sB Ising system with a transverse crystal field are studiedby use of the effective-field theory with correlations. The effect of the transverse crystal field on tran...The critical behaviors of a mixed spin-1/2 and spin-sB Ising system with a transverse crystal field are studiedby use of the effective-field theory with correlations. The effect of the transverse crystal field on transition temperaturesis investigated numerically for the honeycomb (z = 3) and square (z = 4) lattices. The results show that there is notricritical point for the system.展开更多
With the help of technique of integration within an ordered product of operators we can fully display the partial trace method to deduce some new density operators of light field. The general form of single-mode densi...With the help of technique of integration within an ordered product of operators we can fully display the partial trace method to deduce some new density operators of light field. The general form of single-mode density operator is derived in this way from a normalized two-mode generalized squeezed pure state density operator.展开更多
文摘We conduct a theoretical study on the properties of a bound polaron in a quantum well under an electric field using linear combination operator and unitary transformation methods, which are valid in the whole range of electron-LO phonon coupling. The changing relations between the ground-state energy of the bound polaron in the quantum well and the Coulomb bound potential, the electric field strength, and the well width are derived. The numerical results show that the ground-state energy increases with the increase of the electric field strength and the Coulomb bound potential and decreases as the well width increases.
基金国家自然科学基金，高等学校博士学科点专项科研项目，国家重点实验室基金，CTNP of LHIA National Lab of China，国家'211'工程建设项目，中国博士后科学基金
文摘A systematic theory on the appropriate spin operators for the relativistic states is developed. For a massive relativistic particle with arbitrary nonzero spin, the spin operator should be replaced with the relativistic one, which is called in this paper as moving spin. Further the concept of moving spin is discussed in the quantum field theory. A new operator, field quanta spin is defined and in terms of the generators of Poincaré group the moving spin of field system is constructed. It is shown that, in virtue of the two operators, problems in quantum field concerned spin can be neatly settled.
文摘In the coherent thermal state representation we introduce thermal Wigner operator and find that it is'squeezed' under the thermal transformation. The thermal Wigner operator provides us with a new direct and neatapproach for deriving Wigner functions of thermal states.
文摘By virtue of the parabose squeezed operator, propagator of a parabose parametric amplifier, explicit forms of parabose squeezed number states and normalization factors of excitation states on a parabose squeezed vacuum state are calculated, which generalize the relevant results from ordinary Bose statistics to the parabose case.
基金The project supported by Science Foundation of the Ministry of Education of China under Grant No.99026
文摘The critical behaviors of a mixed spin-1/2 and spin-sB Ising system with a transverse crystal field are studiedby use of the effective-field theory with correlations. The effect of the transverse crystal field on transition temperaturesis investigated numerically for the honeycomb (z = 3) and square (z = 4) lattices. The results show that there is notricritical point for the system.
基金Supported by the President Foundation of Chinese Academy of Science and National Natural Science Foundation of China under Grant Nos.10775097 and 10874174
文摘With the help of technique of integration within an ordered product of operators we can fully display the partial trace method to deduce some new density operators of light field. The general form of single-mode density operator is derived in this way from a normalized two-mode generalized squeezed pure state density operator.
