  Formation of electron vortices and momentum spirals in photodetachment of the
H$^-$ anion driven by isolated ultrashort laser pulses of circular polarization
or by pairs of such pulses (of either corotating or counterrotating
polarizations) are analyzed under the scope of the strong-field approximation.
It is demonstrated that the carrier-envelope phase (CEP) and helicity of each
individual pulse can be used to actively manipulate and control the vortical
pattern in the probability amplitude of photodetachment. Specifically, the
two-dimensional mappings of probability amplitude can be rotated in the
polarization plane with changing the CEP of the driving pulse (or two
corotating pulses); thus, offering a new tool of field characterization.
Furthermore, it is shown that the formation of spirals or annihilation of
vortices relates directly to the time-reversal symmetry of the laser field,
which is realized by a pair of pulses with opposite helicities and CEPs.
