In this unified model,we introduce the electron-phonon coupling time(tie) and laser pulse width(tp).For long pulses,it can substitute for the traditional thermal conduction model;while for ultrashort pulses,it can sub...In this unified model,we introduce the electron-phonon coupling time(tie) and laser pulse width(tp).For long pulses,it can substitute for the traditional thermal conduction model;while for ultrashort pulses,it can substitute for the standard two-temperature model.As an example of the gold target,we get the dependence of the electron and ion temperature evolvement on the time and position by solving the thermal conduction equation using the finite-difference time-domain(FDTD) method.It is in good agreement with experimental data.We obtain the critical temperature of the onset of ablation using the Saha equation and then obtain the theoretical value of the laser ablation threshold when the laser pulse width ranges from nano-second to femtosecond timescale,which consists well with the experimental data.展开更多
A new ansatz is presentedfor analytic study of the properties of the Holstein model. New analytic resultsfor the polaronic band structure, ground state energy, phonon distribution, hopping probability of electron, and...A new ansatz is presentedfor analytic study of the properties of the Holstein model. New analytic resultsfor the polaronic band structure, ground state energy, phonon distribution, hopping probability of electron, and effectivemasses, of the Holstein molecular crystal model, are given in one dimension. All the analytic results obtained are inaccord with the numerical results completed recently and valid both in the adiabatic and nonadiabatic regimes, andaccurate enough in the region of validity.展开更多
文摘In this unified model,we introduce the electron-phonon coupling time(tie) and laser pulse width(tp).For long pulses,it can substitute for the traditional thermal conduction model;while for ultrashort pulses,it can substitute for the standard two-temperature model.As an example of the gold target,we get the dependence of the electron and ion temperature evolvement on the time and position by solving the thermal conduction equation using the finite-difference time-domain(FDTD) method.It is in good agreement with experimental data.We obtain the critical temperature of the onset of ablation using the Saha equation and then obtain the theoretical value of the laser ablation threshold when the laser pulse width ranges from nano-second to femtosecond timescale,which consists well with the experimental data.
文摘A new ansatz is presentedfor analytic study of the properties of the Holstein model. New analytic resultsfor the polaronic band structure, ground state energy, phonon distribution, hopping probability of electron, and effectivemasses, of the Holstein molecular crystal model, are given in one dimension. All the analytic results obtained are inaccord with the numerical results completed recently and valid both in the adiabatic and nonadiabatic regimes, andaccurate enough in the region of validity.
