We investigate the nonlinear thermal transport properties of a single interacting quantum dot with two energy levels tunnel-coupled to two electrodes using nonequilibrium Green function method and Hartree-Fock decoupl...We investigate the nonlinear thermal transport properties of a single interacting quantum dot with two energy levels tunnel-coupled to two electrodes using nonequilibrium Green function method and Hartree-Fock decoupling approximation. In the case of asymmetric tunnel-couplings to two electrodes, for example, when the upper level of the quantum dot is open for transport, whereas the lower level is blocked, our calculations predict a strong asymmetry for the heat （energy） current, which shows that the quantum dot system may act as a thermal rectifier in this specific situation.展开更多
It is suggested that the extremely large oxygen isotopic Tc shift recently reported in YBa2Cu3O7 may not be an intrinsic mass effect related to the mechanism but due to the small difference of the oxygen contents.
We study the effect of electron-phonon interaction on current and zero-frequency shot noise in resonant tunnelling through a series triple-quantum-dot coupling to a local phonon mode by means of a nonperturbative mapp...We study the effect of electron-phonon interaction on current and zero-frequency shot noise in resonant tunnelling through a series triple-quantum-dot coupling to a local phonon mode by means of a nonperturbative mapping technique along with the Green function formulation. By fixing the energy difference between the first two quantum dots to be equal to phonon frequency and sweeping the level of the third quantum dot, we find a largely enhanced current spectrum due to phonon effect, and in particular we predict current peaks corresponding to phonon-absorption and phonon-emission assisted resonant tunnelling processes, which show that this system can be acted as a sensitive phonon-signal detector or as a cascade phonon generator.展开更多
Ⅰ. INTRODUCTIONIt has been shown experimentally that the electrical resistivity of A15 compounds like Nb3Sn, Nb3Al and Nb3Ge can well be described by the formula ρ=ρ0+αT2 over the temperature range from their Tc t...Ⅰ. INTRODUCTIONIt has been shown experimentally that the electrical resistivity of A15 compounds like Nb3Sn, Nb3Al and Nb3Ge can well be described by the formula ρ=ρ0+αT2 over the temperature range from their Tc to some 50K, and that the resistivity of V3Si exhibits only a little more rapid increase with temperature. On the other hand,展开更多
We examine the temperature dependence of acoustic-phonon-induced magnetoresistance oscillations in a high-mobility GaAs-based quantum well with conventional transverse and longitudinal phonon modes,using a model in wh...We examine the temperature dependence of acoustic-phonon-induced magnetoresistance oscillations in a high-mobility GaAs-based quantum well with conventional transverse and longitudinal phonon modes,using a model in which the temperature increase of the Landau level broadening or the single-particle scattering rate 1/τ;is attributed to the enhancement of electron-phonon scattering with rising temperature.The non-monotonic temperature behavior, showing an optimal temperature at which a given order of oscillation amplitude exhibits a maximum and the shift of the main resistance peak to higher magnetic field with rising temperature,is produced,in agreement with recent experimental findings.展开更多
基金Supported by the National Natural Science Foundation of China, the Shanghai Municipal Commission of Science and Technology, the Shanghai Pujiang Programme, and the Programme for New Century Excellent Talents in University （NCET）.
文摘We investigate the nonlinear thermal transport properties of a single interacting quantum dot with two energy levels tunnel-coupled to two electrodes using nonequilibrium Green function method and Hartree-Fock decoupling approximation. In the case of asymmetric tunnel-couplings to two electrodes, for example, when the upper level of the quantum dot is open for transport, whereas the lower level is blocked, our calculations predict a strong asymmetry for the heat （energy） current, which shows that the quantum dot system may act as a thermal rectifier in this specific situation.
基金This work was supported by National Science Fund of China.
文摘It is suggested that the extremely large oxygen isotopic Tc shift recently reported in YBa2Cu3O7 may not be an intrinsic mass effect related to the mechanism but due to the small difference of the oxygen contents.
基金Supported by the National Natural Science Foundation of China under Grant No , the Shanghai Municipal Commission of Science and Technology under Grant No , the Shanghai Pujiang Programme under Grant No , and the New Century Excellent Talent Project （NCET） of the Ministry of Education of China under Grant No .
文摘We study the effect of electron-phonon interaction on current and zero-frequency shot noise in resonant tunnelling through a series triple-quantum-dot coupling to a local phonon mode by means of a nonperturbative mapping technique along with the Green function formulation. By fixing the energy difference between the first two quantum dots to be equal to phonon frequency and sweeping the level of the third quantum dot, we find a largely enhanced current spectrum due to phonon effect, and in particular we predict current peaks corresponding to phonon-absorption and phonon-emission assisted resonant tunnelling processes, which show that this system can be acted as a sensitive phonon-signal detector or as a cascade phonon generator.
文摘Ⅰ. INTRODUCTIONIt has been shown experimentally that the electrical resistivity of A15 compounds like Nb3Sn, Nb3Al and Nb3Ge can well be described by the formula ρ=ρ0+αT2 over the temperature range from their Tc to some 50K, and that the resistivity of V3Si exhibits only a little more rapid increase with temperature. On the other hand,
基金supported by the National Basic Research Program of China(No.2007CB310402)the National Natural Science Foundation of China(No.60721004)+1 种基金the Major Projects(Nos.KGCX1-YW-24,KGCX2-YW-231)the Hundred Scholar Plan of the Chinese Academy of Sciences
文摘We examine the temperature dependence of acoustic-phonon-induced magnetoresistance oscillations in a high-mobility GaAs-based quantum well with conventional transverse and longitudinal phonon modes,using a model in which the temperature increase of the Landau level broadening or the single-particle scattering rate 1/τ;is attributed to the enhancement of electron-phonon scattering with rising temperature.The non-monotonic temperature behavior, showing an optimal temperature at which a given order of oscillation amplitude exhibits a maximum and the shift of the main resistance peak to higher magnetic field with rising temperature,is produced,in agreement with recent experimental findings.
