Invariant‐Based Pulse Design for Three‐Level Systems Without the Rotating‐Wave Approximation

In this paper, a scheme is put forward to design pulses which drive a three‐level system based on the reverse engineering with Lewis‐Riesenfeld invariant theory. The scheme can be applied to a three‐level system even when the rotating‐wave approximation (RWA) can not be used. The amplitudes of pulses and the maximal values of detunings in the system could be easily controlled by adjusting control parameters. We analyze the dynamics of the system by an invariant operator, so additional couplings are unnecessary. Moreover, the approaches to avoid singularity of pulses are studied and several useful results are obtained. We hope the scheme could contribute to fast quantum information processing without RWA.