For investigating dynamic evolution of a mass-varying harmonic oscillator we constitute a ket-bra integrationoperator in coherent state representation and then perform this integral by virtue of the technique of integ...For investigating dynamic evolution of a mass-varying harmonic oscillator we constitute a ket-bra integrationoperator in coherent state representation and then perform this integral by virtue of the technique of integration withinan ordered product of operators.The normally ordered time evolution operator is thus obtained.We then derive theWigner function of u(t)|n>,where |n> is a Fock state,which exhibits a generalized squeezing,the squeezing effect isrelated to the varying mass with time.展开更多
We consider the covalence characters of the 3d electron with the eg orbital freedoms and put forward a new mechanism of the orbital ordering （00） based on the direct coulomb repulsion in this article. The results sh...We consider the covalence characters of the 3d electron with the eg orbital freedoms and put forward a new mechanism of the orbital ordering （00） based on the direct coulomb repulsion in this article. The results show that the orbital-orbital interaction （OO-I） between the adjacent ions in 180-degree configuration is dominated by the superexchange energy accompanied by a weak orbital-spin coupling, and the OO-I in 90-degree configuration is monitored by the oxygen on-site coulomb repulsion. The ferro-OO is the stable ground state for the one-dimensional chain in the case of the 90-degree configuration.展开更多
The impact of the lattice strain on the charge/orbital ordering state was studied by using a heterostructure composed with elec- tron-doped La0.9Hf0.1MnO3 （LHMO） and ferro- and piezoelectric 0.67Pb（Mgl/3Nb2/3）O3-0...The impact of the lattice strain on the charge/orbital ordering state was studied by using a heterostructure composed with elec- tron-doped La0.9Hf0.1MnO3 （LHMO） and ferro- and piezoelectric 0.67Pb（Mgl/3Nb2/3）O3-0.33PbTiO3. The ferroelectric poling induces a significant reduction in the biaxial tensile strain in the LHMO film, leading to a decrease in the film resistance over the whole temperature range and an increase in the insulator to metal transition temperature TIM. The resistance of LHMO film exhibits different responses to the external electric fields and lattice deformation, which is attributed to the coactions of con- verse piezoelectric effect and ferroelectric polarity effect. The modification of charge/orbital ordering phase by the electric fields and ferroelectric polarization suggests that the unstable states in the manganites are sensitive to strain effects.展开更多
基金Supported by National Natural Science Foundation of China under Grant No.10874174
文摘For investigating dynamic evolution of a mass-varying harmonic oscillator we constitute a ket-bra integrationoperator in coherent state representation and then perform this integral by virtue of the technique of integration withinan ordered product of operators.The normally ordered time evolution operator is thus obtained.We then derive theWigner function of u(t)|n>,where |n> is a Fock state,which exhibits a generalized squeezing,the squeezing effect isrelated to the varying mass with time.
文摘We consider the covalence characters of the 3d electron with the eg orbital freedoms and put forward a new mechanism of the orbital ordering （00） based on the direct coulomb repulsion in this article. The results show that the orbital-orbital interaction （OO-I） between the adjacent ions in 180-degree configuration is dominated by the superexchange energy accompanied by a weak orbital-spin coupling, and the OO-I in 90-degree configuration is monitored by the oxygen on-site coulomb repulsion. The ferro-OO is the stable ground state for the one-dimensional chain in the case of the 90-degree configuration.
基金supported by the Research Grant Council of Hong Kong(Grant No. HKU 702409P)the Seed Funding by the University of Hong Kong
文摘The impact of the lattice strain on the charge/orbital ordering state was studied by using a heterostructure composed with elec- tron-doped La0.9Hf0.1MnO3 （LHMO） and ferro- and piezoelectric 0.67Pb（Mgl/3Nb2/3）O3-0.33PbTiO3. The ferroelectric poling induces a significant reduction in the biaxial tensile strain in the LHMO film, leading to a decrease in the film resistance over the whole temperature range and an increase in the insulator to metal transition temperature TIM. The resistance of LHMO film exhibits different responses to the external electric fields and lattice deformation, which is attributed to the coactions of con- verse piezoelectric effect and ferroelectric polarity effect. The modification of charge/orbital ordering phase by the electric fields and ferroelectric polarization suggests that the unstable states in the manganites are sensitive to strain effects.
