Two-photon resonant transition in a single atomic spin pair Er-T

The interaction between radiation and matter involving the absorption or emission of multiple photons underpins various modern technologies, including Raman scattering and harmonic generation. The coherent control of quantum states through two-photon processes facilitates the creation of quantum entanglement [1, 2, 3], a cornerstone of quantum information processing. Despite the significance, the coherent control of such a process in atomic spin qubits remains largely unexplored [4-7]. In this talk, we present our recent experimental results demonstrating the observation of a two-photon process in a pair of Erbium (Er) and Titanium (Ti) spins on a MgO surface. Using pulsed electron spin resonance, we achieve coherent control between the spin states of the Er-Ti pair using two-photon interaction, identifying a novel way for implementation of quantum gates to atomic spin qubits on a surface.



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[7] Stefano Reale et al., Phys. Rev. B 107, 045427 (2023)