中文题目: 利用类维格纳分布函数方法研究阈上电离
外文题目: Study of above-threshold ionization by "Wigner-distribution-like function" method
作者: 郭丽; 韩申生; 陈京
刊名: 物理学报
年: 2016 卷: 65 期: 22 文章编号：223203
中文关键词:
阈上电离; 类维格纳分布函数; 时间-能量分布; 隧穿电离
英文关键词:
above-threshold ionization; Wigner-distribution-like function; time-energy distribution; tunneling ionization
MULTIPHOTON IONIZATION; FIELD
中文摘要:
提出了一种类维格纳分布函数并用该分布函数计算了氢原子在少周期、不同偏振方向和不同激光频率的激光脉冲中电离后光电子的各种分布:线偏振下的时间-能量分布、时间电离率分布和椭圆偏振下的时间-出射角分布、角度分布和时间电离率分布.结果显示:随着激光频率降低,所有分布清楚直观地展现出电子从多光子区域到隧穿区域的转变过程.对线偏振情况,伴随着这种转变,电离时间与最终动量之间的半经典关系与时间-能量分布越来越一致.同时,时间-能量分布清楚地展现了隧穿区域中的干涉结构,并给出了干涉原因是由不同时刻电离出的具有相同能量的电

英文摘要:
A Wigner-distribution -like function is proposed to obtain various distributions of photoelectron emitted from H atoms in few-cycle laser pulses with different frequencies: time-energy distribution, time ionization distribution for linearly polarized laser field and time-emission angle distribution, angular distribution, and time ionization distribution for elliptically polarized laser field. With decreasing frequency, all the distributions clearly show a transition of ionization process from the multi-photon regime to the tunneling regime. For the case of linearly polarized laser pulse, accompanying this transition, the semiclassical relationship between the ionization moment and the final drift energy is becoming more and more close to the time-energy distribution. Meanwhile, the time-energy distribution clearly shows the interference structures in the tunneling regime, which can be attributed to the interference between the electrons with the same energy ejected at different times. For the case of elliptically polarized laser pulse, both the angular offset in the angular distribution and the time offset in the time ionization distribution are obtained by comparing the quantum calculation with the semi-classical result. The results show that the time offset is much smaller than the angular offset. This indicates that the "attoclock" technique which is based on the correspondence between two offsets is in principle inaccurate. Furthermore, the time offset can be both positive and negative. So this time offset cannot be interpreted as the tunneling time.


文献类型: 期刊论文
正文语种: Chinese
收录类别: SCIEI
DOI: 10.7498/aps.65.223203


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