标题： 用于压电氮化铝中高-Qm 机械缺陷模式的膜声子晶体 显示英文标题

标题： Membrane phononic crystals for high-Qm mechanical defect modes in piezoelectric aluminum nitride

摘要： 具有异常低耗散的纳米机械谐振器正在推动基于机械的传感器和量子技术的发展。 这些进步的关键在于局域声子模式的工程设计，这些模式与环境良好隔离，即表现出高的机械品质因数 Qm。 从应变薄膜中制造的膜声子晶体可以在兆赫兹频率下实现高 Qm 的单个或多个局域声子缺陷模式。 这些缺陷模式可以有效地与垂直光相互作用或耦合到微波量子电路，从而实现对其运动的读取和控制。 当膜声子晶体由晶体薄膜制成时，它们可以提供内置功能。 我们展示了一种在应变的 90 纳米厚的氮化铝（AlN）薄膜中实现的膜声子晶体，AlN 是一种晶体压电材料。 我们在室温下设计了一个 1.8 兆赫兹的高 Qm 局域声子缺陷模式，其 Qxf 乘积为 1.5x10^13 赫兹。 在未来器件中，AlN 的内置压电性可用于直接耦合到量子比特或对机械模式频率、缺陷模式耦合或声学带隙进行原位调谐，这些可以作为可调声子电路或低噪声传感器的构建模块。 显示英文摘要

摘要： Nanomechanical resonators with exceptionally low dissipation are advancing mechanics-based sensors and quantum technologies. The key for these advances is the engineering of localized phononic modes that are well-isolated from the environment, i.e., that exhibit a high mechanical quality factor, Qm. Membrane phononic crystals fabricated from strained thin films can realize high-Qm single or multiple localized phononic defect modes at MHz frequencies. These defect modes can be efficiently interfaced with out-of-plane light or coupled to a microwave quantum circuit, enabling readout and control of their motion. When membrane phononic crystals are fabricated from a crystalline film, they could offer built-in functionality. We demonstrate a membrane phononic crystal realized in a strained 90 nm-thin film of aluminum nitride (AlN), which is a crystalline piezoelectric material. We engineer a high-Qm localized phononic defect mode at 1.8 MHz with a Qxf-product of 1.5x10^13 Hz at room temperature. In future devices, the built-in piezoelectricity of AlN can be utilized for direct coupling to qubits or in-situ tuning of mechanical mode frequencies, defect mode couplings, or acoustic bandgaps, which can be used as building blocks of tunable phononic circuits or low-noise sensors.