Positron-impact ionisation of atomic hydrogen in the presence of a bichromatic laser field  

作　　者：娄俊 李书民 

机构地区：[1]Department of Modern Physics,University of Science and Technology of China [2]Institut fr Theoretische Physik,Universitt Heidelberg,Philosophenweg 16,69120 Heidelberg,Germany

出　　处：《Chinese Physics B》2010年第11期347-350,共4页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 10874169 and 10674125);the National Basic Research Program of China (Grant Nos. 2007CB925200 and 2010CB923301);the Deutsche Forschungsgemeinschaft for the support (Contract No. 446CHV113/261/0-1) during his stay in Germany

摘　　要：The positron impact-ionisation of atomic hydrogen in the presence of a linearly polarised bichromatic field is investigated in the first Born approximation. The field is composed of a fundamental frequency and its second harmonic. The state of positron in the field is described by the Volkov wavefunction, and the continuum state of the ejected electron is described by the Coulomb-Volkov wavefunction. The dressed ground state of target is a first order time-dependent perturbative wavefunction. The triple differential cross sections and their dependencies on laser field parameters are discussed and compared with the results modified by a monochromatic field. Numerical results show that the coherent phase control is significant and the laser-assisted ionisation cross sections caused by positron and electron are different.The positron impact-ionisation of atomic hydrogen in the presence of a linearly polarised bichromatic field is investigated in the first Born approximation. The field is composed of a fundamental frequency and its second harmonic. The state of positron in the field is described by the Volkov wavefunction, and the continuum state of the ejected electron is described by the Coulomb-Volkov wavefunction. The dressed ground state of target is a first order time-dependent perturbative wavefunction. The triple differential cross sections and their dependencies on laser field parameters are discussed and compared with the results modified by a monochromatic field. Numerical results show that the coherent phase control is significant and the laser-assisted ionisation cross sections caused by positron and electron are different.

关 键 词：bichromatic laser field POSITRON impact-ionisation 

分 类 号：O562.5[理学—原子与分子物理]