Multicolor detachment of a negative ion in the presence of a static magnetic field

The photodetachment of a negative ion by a weak electromagnetic field, with a frequency near the photodetachment threshold, in the presence of a static magnetic field and a low-frequency (LF) bichromatic electromagnetic field, whose components have commensurate frequencies, is investigated. The case is treated in which the ejected electron may exchange a large number of photons of the LF field. It is found that when the relative phase of the LF field components is zero, the photoelectron flux along the magnetic field in the forward direction is different from the one in the backward direction. Moreover, the case is addressed in which the photodetachment is caused by the action of two weak fields whose frequencies differ by a small integer multiple of the frequency of a monochromatic LF assisting field, in the regime in which the cyclotron frequency is a multiple of the frequency of the LF field.