Dynamical Suppression of Unwanted Transitions in Multistate Quantum Systems

We propose a method to suppress unwanted transition channels and achieve perfect population transfer in multistate quantum systems by using composite pulse sequences. Unwanted transition paths may be present due to imperfect light polarization, misalignment of the quantization axis, spatial inhomogeneity of the trapping fields, off-resonant couplings, etc., or they may be merely unavoidable, e. g., due to perturbing excitations in molecules and solids. Compensation of separate or simultaneous deviations in polarization, pulse area, and detuning is demonstrated, even when these deviations are unknown, in three-state V and Xi (ladder) systems and in a four-state Y system. DOI: 10.1103/PhysRevLett.110.133002