The high-order above-threshold ionization (ATI) by a few-cycle pulse in asymmetric molecules has been investigated by solving the time-dependent Schrödinger equation. The resulting high-energy ATI spectra are very sensitive to the laser’s carrier-envelope phase (CEP) and analyzed in terms of the classical model. The left-right asymmetry of ATI yields of asymmetric molecules for high energies is different from that of atoms, resulting from the existence of an asymmetric potential well, and is explained by studying the molecules in the presence of a static electric field. The asymmetry for asymmetric molecules is expected to be used for measuring the CEP more accurately than for atoms.

• Received 25 September 2007

DOI:https://doi.org/10.1103/PhysRevA.77.013408