Asymmetry in the Strong-field Photodetachment of H^- by Linearly Polarized Few-cycle Pulses

Photodetachment of H^- irradiated by linearly polarized few-cycle laser field is investigated by time-dependent Schr?dinger equation numerically. The photo-electron left-right asym-metry parameter as a function of carrier-envelop (CE) phase of few-cycle pulses is attained. We confirm the asymmetry of photoelectron distribution in H^- photodetachment and find that the maximal asymmetry parameter of H^- is equal to that of H atom under the same conditions but the corresponding CE phases are quite different. Thus a CE phase shift ap-pears. Compared to that of H atom and field free electron, the zero asymmetry CE phase shift is sensitively affected by Coulomb field. The Coulomb effect on the asymmetry of H^- photodetachment mainly behaves in the CE phase shift of H^- instead of the amplitude of asymmetry parameter curve.