在空间均匀含时的强外场下真空正负电子对产生的研究中,从散射势转变点的角度,严格证明了源于量子Vlasov方程的低密度近似方法(low density approximation,LDA)与半经典的WKB(Wentzel-Kramers-Brillouin)方法等价.通过对典型例子进行数...在空间均匀含时的强外场下真空正负电子对产生的研究中,从散射势转变点的角度,严格证明了源于量子Vlasov方程的低密度近似方法(low density approximation,LDA)与半经典的WKB(Wentzel-Kramers-Brillouin)方法等价.通过对典型例子进行数值计算和说明,对这2种方法的等价性进行了检验.当有较多转变点时,WKB积分变得烦琐,相较而言,LDA更具有计算优势.本研究将量子动力学过程和量子隧穿过程联系起来,有助于深入理解强场下真空中正负电子对的产生过程.展开更多
The rapidly developing reserach field on dusty plasmas is introduced and reviewed.Two lmportant aspects of current dusty plasma investigations for collective waves in dusty plas-mas and dusty plasma crystals are mainl...The rapidly developing reserach field on dusty plasmas is introduced and reviewed.Two lmportant aspects of current dusty plasma investigations for collective waves in dusty plas-mas and dusty plasma crystals are mainly introduced and discussed. Some possible applicationsand effects which havc already occurred in many interdisciplinary areas are also mentioned and ommented.展开更多
By using the worldline instanton method we investigate the electron-positron pair production rate from a vacuum in the presence of a time-dependent field with general elliptic polarization.It is found that as field po...By using the worldline instanton method we investigate the electron-positron pair production rate from a vacuum in the presence of a time-dependent field with general elliptic polarization.It is found that as field polarization changes from a linear to a circular one,the pair production rate would change to some extent.When field strength is weak while frequency is high,the pair production rate changes significantly with polarization.However,when field strength is strong while frequency is low,the pair production rate from a vacuum is insensitive to field polarization and the results of the pair production rate are the same as those in a constant field.Our results are compared with previous work and the implications of our study are briefly discussed.展开更多
文摘在空间均匀含时的强外场下真空正负电子对产生的研究中,从散射势转变点的角度,严格证明了源于量子Vlasov方程的低密度近似方法(low density approximation,LDA)与半经典的WKB(Wentzel-Kramers-Brillouin)方法等价.通过对典型例子进行数值计算和说明,对这2种方法的等价性进行了检验.当有较多转变点时,WKB积分变得烦琐,相较而言,LDA更具有计算优势.本研究将量子动力学过程和量子隧穿过程联系起来,有助于深入理解强场下真空中正负电子对的产生过程.
文摘The rapidly developing reserach field on dusty plasmas is introduced and reviewed.Two lmportant aspects of current dusty plasma investigations for collective waves in dusty plas-mas and dusty plasma crystals are mainly introduced and discussed. Some possible applicationsand effects which havc already occurred in many interdisciplinary areas are also mentioned and ommented.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10834008,10965006,11175023 and 11165014the Fundamental Research Funds for the Central Universities(FRFCU).
文摘By using the worldline instanton method we investigate the electron-positron pair production rate from a vacuum in the presence of a time-dependent field with general elliptic polarization.It is found that as field polarization changes from a linear to a circular one,the pair production rate would change to some extent.When field strength is weak while frequency is high,the pair production rate changes significantly with polarization.However,when field strength is strong while frequency is low,the pair production rate from a vacuum is insensitive to field polarization and the results of the pair production rate are the same as those in a constant field.Our results are compared with previous work and the implications of our study are briefly discussed.
