Fidelity of fast nonadiabatic Landau–Zener–Stückelberg–Majorana quantum logic gates with decoherence

A conventional realization of quantum logic gates relies on resonant driving and Rabi oscillations of the qubit states. We explore an alternative control paradigm based on Landau–Zener–Stückelberg–Majorana (LZSM) interferometry, where non-resonant large-amplitude driving produces gate operations through alternating adiabatic evolution and nonadiabatic transitions. Compared to the conventional Rabi approach, LZSM gates employ non-resonant driving with large amplitudes and only a few drive periods, which can simplify control hardware and shorten operation times. Related nonadiabatic gate concepts have also been demonstrated experimentally in superconducting circuits, showing partial resilience to low-frequency noise [1].

Expanding our recent study [2], we include modelling of relaxation and dephasing effects. We investigate gate fidelities and robustness for realistic parameters in the presence of decoherence to assess the potential of using the LZSM-based realization of quantum logic gates in quantum computers experimentally.

[1] D. L. Campbell et al., Universal Nonadiabatic Control of Small-Gap Superconducting Qubits, Phys. Rev. X 10, 041051 (2020).

[2] A. I. Ryzhov, O. V. Ivakhnenko, S. N. Shevchenko, M. F. Gonzalez-Zalba, Franco Nori, Alternative fast quantum logic gates using nonadiabatic Landau-Zener-Stückelberg-Majorana transitions, Phys. Rev. Research 6, 033340 (2024).