EFFECT OF TIME-REVERSAL IN THE MAGNETIZATION OF AN ATOM BY A RESONANTLIGHT-PULSE

It is shown that the even dependence of the light-induced magnetic mom ent on the detuning omega-omega(ba) from resonance in the case of a ci rcularly polarized pulse and an isotropic initial state of the atom an d the odd dependence on omega-omega(ba) in the case of a linearly pola rized pulse and an anisotropic initial state in the form of alignment of the atom are consequences of the symmetry under time reversal t-->- t and of the initial conditions at time t=0. In a number of cases, thi s fundamental law makes it possible to determine the vector properties of a light-induced magnetic moment and its dependence on the time t a nd omega-omega(ba) without solving the equation for the density matrix in detail and without calculating the sum over the projections of the angular momenta in the formula for the magnetization of an atom by li ght. (C) 1997 American Institute of Physics.