The expression of the ground-state energy of the electron coupled simultaneously with a Coulomb potential and a longitudinal-optical phonon field in parabolic quantum dots and wires is derived within the framework of ...The expression of the ground-state energy of the electron coupled simultaneously with a Coulomb potential and a longitudinal-optical phonon field in parabolic quantum dots and wires is derived within the framework of Feynman variational path integral theory.We obtain a general result with arbitrary electron-phonon coupling constant,Coulomb binding parameters,and confining potential strength,which could be used for further numerical calculation of polaron properties.Moreover,it is shown that all the previous path-integral formulae for free polarons,bound polarons,and polarons confined in parabolic quantum dots and wires can be recovered in the present formalism.展开更多
The second-order phase transition in the two-dimensional(2D)classical Coulomb gas of half-integer charges on a square lattice is investigated by using Monte Carlo simulations.Based on the finite-size scaling analysis,...The second-order phase transition in the two-dimensional(2D)classical Coulomb gas of half-integer charges on a square lattice is investigated by using Monte Carlo simulations.Based on the finite-size scaling analysis,we estimate the second-order phase transition temperature Tc and the static critical exponentsβand v with a new numerical analysis method.More precise critical temperature Tc=0.1311(2)and critical exponentsβ/v=0.1152(12)and v=0.857(15)are obtained.The estimated value of v indicates that the charge lattice melting transition is different from the pure 2D Ising transition.展开更多
We study the ground state of a two-dimensional vortex system with random pinnings by cooling the vortex system to zero temperature.The peak of structure factor S(k)of vortices increases with vortex density B but decre...We study the ground state of a two-dimensional vortex system with random pinnings by cooling the vortex system to zero temperature.The peak of structure factor S(k)of vortices increases with vortex density B but decreases with pin density BФ,indicating that the vortex lattice becomes better and better ordered with increasing B.When B>BФ,the triangular vortex lattice is observed away from the pins.Repulsive vortex interactions destroy the Mott insulator phase which is predicted to occur at B=BФ.The crossover line between the strong Bose glass and the weak Bose glass is nearly independent of BФfor small BФ.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.19804009.
文摘The expression of the ground-state energy of the electron coupled simultaneously with a Coulomb potential and a longitudinal-optical phonon field in parabolic quantum dots and wires is derived within the framework of Feynman variational path integral theory.We obtain a general result with arbitrary electron-phonon coupling constant,Coulomb binding parameters,and confining potential strength,which could be used for further numerical calculation of polaron properties.Moreover,it is shown that all the previous path-integral formulae for free polarons,bound polarons,and polarons confined in parabolic quantum dots and wires can be recovered in the present formalism.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10075039 and 19904009the Ministry of Science and Technology of China(NKBRSF-G19990646).
文摘The second-order phase transition in the two-dimensional(2D)classical Coulomb gas of half-integer charges on a square lattice is investigated by using Monte Carlo simulations.Based on the finite-size scaling analysis,we estimate the second-order phase transition temperature Tc and the static critical exponentsβand v with a new numerical analysis method.More precise critical temperature Tc=0.1311(2)and critical exponentsβ/v=0.1152(12)and v=0.857(15)are obtained.The estimated value of v indicates that the charge lattice melting transition is different from the pure 2D Ising transition.
基金Supported by the Ministry of Science and Technology of China(NKBRSF-G19990646)the National Natural Science Foundation of China under Grant No.19904009Zhejiang Province Scientific Foundation under Grant No.199031.
文摘We study the ground state of a two-dimensional vortex system with random pinnings by cooling the vortex system to zero temperature.The peak of structure factor S(k)of vortices increases with vortex density B but decreases with pin density BФ,indicating that the vortex lattice becomes better and better ordered with increasing B.When B>BФ,the triangular vortex lattice is observed away from the pins.Repulsive vortex interactions destroy the Mott insulator phase which is predicted to occur at B=BФ.The crossover line between the strong Bose glass and the weak Bose glass is nearly independent of BФfor small BФ.
