Coherent state transfer between superconducting qubits via stimulated Raman adiabatic passage

Abstract

Coherent quantum state transfer is a vital step in quantum information processing. Based on the stimulated Raman adiabatic passage (STIRAP), we realize robust quantum state transfer between two superconducting qubits, mediated by a tunable coupler. Utilizing parametric coupling techniques, we construct the STIRAP Hamiltonian by modulating the coupler frequency. A population transfer fidelity of 95.1 (±2.0)% is achieved and is consistent with the numerical simulation result of 95.4%. By preparing the initial state in the maximal superposition state of one qubit, we research how the phase of the transferred state is related to the modulation pulses. We also find that the transfer process is robust against the fluctuation of modulation frequency. Numerical simulation confirms that our state transfer scheme is more robust than non-adiabatic protocols.