Fast quantum logic gates using nonadiabatic Landau-Zener-Stückelberg-Majorana transitions*

A conventional realization of quantum logic gates and control is based on resonant driving, which causes periodic resonant Rabi oscillations of the occupation probability of the quantum system. We study an alternative paradigm for implementing quantum logic gates based on Landau-Zener-Stückelberg-Majorana (LZSM) interferometry with non-resonant driving and the alternation of adiabatic evolution and non-adiabatic transitions. Compared to the Rabi oscillations method, the main differences are a non-resonant frequency, large amplitude, and a small number of periods in the external driving.

We explore the dynamics of a multilevel quantum system under LZSM drives, demonstrate the implementation of single-qubit X, Y, H, and two-qubit iSWAP, CNOT gates, explore optimization of the parameters for increasing the gate speed and fidelity, and compare the theoretical error rates between the conventional Rabi-based and considered LZSM-based gates. The parameters of the external driving required for implementing a specific gate are defined using the adiabatic-impulse model. The LZSM approach can be applied to a large variety of multi-level quantum systems and external driving, providing a method to control the dynamics and implement quantum logic gates on them.

[1] A.I. Ryzhov, et.al., Alternative fast quantum logic gates using nonadiabatic Landau-Zener-Stückelberg-Majorana transitions, arXiv:2310.17932.