论文标题
在C-QED设置中冷却具有Transmon Qubit的机械谐振器的前景
Prospects of cooling a mechanical resonator with a transmon qubit in c-QED setup
论文作者
论文摘要
基于超导码位的混合设备已成为控制宏观共振器量子状态的有前途的平台。量子线添加的非线性可能是这种控制的宝贵资源。在这里，我们研究了由机械谐振器纵向耦合到Transmon Qubit的混合系统。量子读数可以通过耦合到读取模式（例如在C-AS设置中）来完成。机械谐振器和跨量矩之间的耦合可以通过调节鱿鱼电感来实现。在这样的三方系统中，当所有三个模式都分散耦合时，我们分析了机械模式的稳态占用。我们使用量子噪声和lindblad形式主义，表明机械模式的边带冷却至基态是可以实现的。我们进一步在实验上证明，在分散极限内可以测量热机械运动，同时保持量子和机械模式之间的较大耦合。我们的理论计算表明，在这种混合设备中，单光子强耦合在实验范围内。
Hybrid devices based on the superconducting qubits have emerged as a promising platform for controlling the quantum states of macroscopic resonators. The nonlinearity added by a qubit can be a valuable resource for such control. Here we study a hybrid system consisting of a mechanical resonator longitudinally coupled to a transmon qubit. The qubit readout can be done by coupling to a readout mode like in c-QED setup. The coupling between the mechanical resonator and transmon qubit can be implemented by modulation of the SQUID inductance. In such a tri-partite system, we analyze the steady-state occupation of the mechanical mode when all three modes are dispersively coupled. We use the quantum-noise and the Lindblad formalism to show that the sideband cooling of the mechanical mode to its ground state is achievable. We further experimentally demonstrate that measurements of the thermomechanical motion is possible in the dispersive limit, while maintaining a large coupling between qubit and mechanical mode. Our theoretical calculations suggest that single-photon strong coupling is within the experimental reach in such hybrid devices.
