With a stereo above-threshold ionization (ATI) apparatus, we systematically investigate the carrier-envelope phase (CEP) dependence of the photoelectron kinetic energy spectra from high-order ATI of Xe atom subject to a strong few-cycle laser field. Our measurements reveal a prominent step structure and a maximum in the photoelectron kinetic energy dependence of the yield asymmetry. The observed structures can be well reproduced by the numerical solution of time-dependent Schrdinger equation (TDSE) and the improved strong field approximation (ISFA) theory. According to our analysis, the step structure can be ascribed to the interference of long and short orbits, while the maximum is closely related to the distinct kinetic energy distributions of photoelectrons which elastically scatter on the core at odd and even returns. Our work provides a more comprehensive understanding of the CEP effects on high energy photoelectron emissions in a few-cycle laser field.

使用立体超阈值电离 (ATI) 装置，我们系统地研究了受强少周期激光场影响的 Xe 原子高阶 ATI 光电子动能谱的载流子包络相位 (CEP) 依赖性。我们的测量揭示了显着的阶梯结构和产率不对称性的光电子动能依赖性的最大值。时变薛定谔方程（TDSE）的数值解和改进的强场近似（ISFA）理论可以很好地再现观察到的结构。根据我们的分析，阶梯结构可以归因于长短轨道的干涉，而最大值与光电子在奇数和偶数返回时弹性散射在核心上的不同动能分布密切相关。