講演情報
[23p-21B-7]Phonon-matching tuning in a piezoelectrically driven double hybrid nanocavity
〇(P)Michele Diego1, Byunggi Kim1, Matteo Pirro1, Sebastian Volz2, Masahiro Nomura1 (1.IIS Univ. of Tokyo, 2.LIMMS (IIS - Univ. of Tokyo))
キーワード：
Phononic cavity、Nanoresonators、Diamond color centers
Efficiently exciting and controlling phonons in nanoresonators represent a fundamental challenge for quantum applications1. Here, we present a theoretical approach demonstrating a novel strategy to excite mechanical modes within a phononic nanocavity. This is achieved by integrating it with a piezoelectric nanocavity, together creating a doubly-hybrid-cavity (DHC). Patterning both cavities introduces a substantial number of structural parameters in the DHC. This feature makes the system well-suited for design optimization through a genetic algorithm. As a result, we can match the phononic properties of the two individual cavities, enabling them to function coordinately in the DHC.First, we customize the individual unit cells, opening a bandgap in the phonon dispersion of the combined unit cell. Then, we engineer the defects in the cavities aiming to adjust the DHC fundamental resonant mode within the bandgap range. This ensures a strong confinement of phonons. Finally, we demonstrate that the piezoelectric cavity can serve as a photon-to-phonon transducer. Non-contact electrodes, indeed, can be employed to efficiently activate phonons within the piezoelectric cavity using the inverse piezoelectric effect. This excitation is subsequently transferred to the diamond cavity, thereby activating the overall resonant mode in the DHC.The phonon-matching concept is introduced in the case of a DHC made by adjoining a diamond and an aluminum nitride nanocavity. The interest in this system resides in the capacity of diamond to host color centers, whose spin transitions can be triggered by mechanical stress2. Consequently, the DHC holds the potential to function as a spin qubit, paving the way for applications in quantum networking.