We conduct a study on the superlinear transport of multilayer graphene channels that partially or completely locate on silicon which is pre-etched by inductively coupled plasma （ICP）. By fabricating a multilayer-gra...We conduct a study on the superlinear transport of multilayer graphene channels that partially or completely locate on silicon which is pre-etched by inductively coupled plasma （ICP）. By fabricating a multilayer-graphene field-effect transistor on a Si/SiO2 substrate, we obtain that the superlinearity results from the interaction between the multilayer graphene sheet and the ICP-etched silicon, In addition, the observed superlinear transport of the device is found to be consistent with the prediction of Schwinger＇s mechanism. In the high bias regime, the values of a increase draxnatically from 1.02 to 1.40. The strength of the electric field corresponding to the on-start of electron-hole pair production is calculated to be 5 × 10^4 Vim. Our work provides an experimental observation of the nonlinear transport of the multilayer graphene.展开更多
Cylindrical and spherical dust-electron-acoustic （DEA） shock waves and double layers in an unmagnetized, col- lisionless, complex or dusty plasma system are carried out. The plasma system is assumed to be composed o...Cylindrical and spherical dust-electron-acoustic （DEA） shock waves and double layers in an unmagnetized, col- lisionless, complex or dusty plasma system are carried out. The plasma system is assumed to be composed of inertial and viscous cold electron fluids, nonextensive distributed hot electrons, Maxwellian ions, and negatively charged stationary dust grains. The standard reductive perturbation technique is used to derive the nonlinear dynamical equations, that is, the nonplanar Burgers equation and the nonplanar further Burgers equation. They are also numerically analyzed to investigate the basic features of shock waves and double layers （DLs）. It is observed that the roles of the viscous cold electron fluids, nonextensivity of hot electrons, and other plasma parameters in this investigation have significantly modified the basic features （such as, polarity, amplitude and width） of the nonplanar DEA shock waves and DLs. It is also observed that the strength of the shock is maximal for the spherical geometry, intermediate for cylindrical geometry, while it is minimal for the planar geometry. The findings of our results obtained from this theoretical investigation may be useful in understanding the nonlinear phenomena associated with the nonplanar DEA waves in both space and laboratory plasmas.展开更多
Some nonlinear behavior in electron cyclotron resonance plasma was investigated using a two-dimension hybrid-mode with self-consistent microwave absorption. The saturation,oscillations of plasma parameters (plasma den...Some nonlinear behavior in electron cyclotron resonance plasma was investigated using a two-dimension hybrid-mode with self-consistent microwave absorption. The saturation,oscillations of plasma parameters (plasma density, potential, electron temperature) versus operating conditions (pressure, power) are discussed. Our simulation results are consistent qualitatively with many experimental measurements.展开更多
Intersubband linear and third-order nonlinear optical properties of conical quantum dots with infinite barrier potential are studied. The electronic structure of conical quantum dots through effective mass approximati...Intersubband linear and third-order nonlinear optical properties of conical quantum dots with infinite barrier potential are studied. The electronic structure of conical quantum dots through effective mass approximation is determined analytically. Linear, nonlinear, and total absorption coefficients, as well as the refractive indices of GaAs conical dots, are calculated. The effects of the size of the dots and of the incident electromagnetic field are investigated. Results show that the total absorption coefficient and the refractive index of the dots largely depend on the size of the dots and on the intensity and polarization of the incident electromaenetic field.展开更多
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFB0402404the High-Tech Research and Development Program of China under Grant Nos 2013AA031401,2015AA016902 and 2015AA016904the National Natural Science Foundation of China under Grant Nos 61674136,61176053,61274069 and 61435002
文摘We conduct a study on the superlinear transport of multilayer graphene channels that partially or completely locate on silicon which is pre-etched by inductively coupled plasma （ICP）. By fabricating a multilayer-graphene field-effect transistor on a Si/SiO2 substrate, we obtain that the superlinearity results from the interaction between the multilayer graphene sheet and the ICP-etched silicon, In addition, the observed superlinear transport of the device is found to be consistent with the prediction of Schwinger＇s mechanism. In the high bias regime, the values of a increase draxnatically from 1.02 to 1.40. The strength of the electric field corresponding to the on-start of electron-hole pair production is calculated to be 5 × 10^4 Vim. Our work provides an experimental observation of the nonlinear transport of the multilayer graphene.
文摘Cylindrical and spherical dust-electron-acoustic （DEA） shock waves and double layers in an unmagnetized, col- lisionless, complex or dusty plasma system are carried out. The plasma system is assumed to be composed of inertial and viscous cold electron fluids, nonextensive distributed hot electrons, Maxwellian ions, and negatively charged stationary dust grains. The standard reductive perturbation technique is used to derive the nonlinear dynamical equations, that is, the nonplanar Burgers equation and the nonplanar further Burgers equation. They are also numerically analyzed to investigate the basic features of shock waves and double layers （DLs）. It is observed that the roles of the viscous cold electron fluids, nonextensivity of hot electrons, and other plasma parameters in this investigation have significantly modified the basic features （such as, polarity, amplitude and width） of the nonplanar DEA shock waves and DLs. It is also observed that the strength of the shock is maximal for the spherical geometry, intermediate for cylindrical geometry, while it is minimal for the planar geometry. The findings of our results obtained from this theoretical investigation may be useful in understanding the nonlinear phenomena associated with the nonplanar DEA waves in both space and laboratory plasmas.
文摘Some nonlinear behavior in electron cyclotron resonance plasma was investigated using a two-dimension hybrid-mode with self-consistent microwave absorption. The saturation,oscillations of plasma parameters (plasma density, potential, electron temperature) versus operating conditions (pressure, power) are discussed. Our simulation results are consistent qualitatively with many experimental measurements.
文摘Intersubband linear and third-order nonlinear optical properties of conical quantum dots with infinite barrier potential are studied. The electronic structure of conical quantum dots through effective mass approximation is determined analytically. Linear, nonlinear, and total absorption coefficients, as well as the refractive indices of GaAs conical dots, are calculated. The effects of the size of the dots and of the incident electromagnetic field are investigated. Results show that the total absorption coefficient and the refractive index of the dots largely depend on the size of the dots and on the intensity and polarization of the incident electromaenetic field.
