Motion detection of a micromechanical resonator embedded in a d.c. SQUID
Motion detection of a micromechanical resonator embedded in a d.c. SQUID
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DOI：
10.1038/nphys1057
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发表时间：
2008-10-01
期刊：
影响因子：
19.6
通讯作者：
van der Zant, H. S. J.
中科院分区：
文献类型：
--
作者：
Etaki, S.;Poot, M.;van der Zant, H. S. J.
超导量子干涉器件（SQUID）是最灵敏的磁通量探测器（1），也被用作量子二能级系统（量子比特）（2）。最近的提议已经探索了一类新的设备，其将微机械谐振器并入SQUID中以实现谐振器基态和量子位的受控纠缠（3），以及允许谐振器模式的冷却和压缩并实现量子限制位置检测（4-10）。尽管这些有趣的可能性，没有实验实现的片上，耦合机械谐振器SQUID系统尚未实现。在这里，我们展示了灵敏的检测嵌入到循环的ad.c.的2 MHz的弯曲谐振器的位置。SQUID。我们在毫开尔文温度下测量谐振器的热运动，实现了10 fm Hz（-1/2）的位移灵敏度和36倍于量子极限的位置分辨率。
Superconducting quantum interference devices (SQUIDs) are the most sensitive detectors of magnetic flux(1) and are also used as quantum two-level systems (qubits)(2). Recent proposals have explored a novel class of devices that incorporate micromechanical resonators into SQUIDs to achieve controlled entanglement of the resonator ground state and a qubit(3) as well as permitting cooling and squeezing of the resonator modes and enabling quantum-limited position detection(4-10). In spite of these intriguing possibilities, no experimental realization of an on-chip, coupled mechanical-resonator-SQUID system has yet been achieved. Here, we demonstrate sensitive detection of the position of a 2 MHz flexural resonator that is embedded into the loop of ad.c. SQUID. We measure the resonator's thermal motion at millikelvin temperatures, achieving an amplifier-limited displacement sensitivity of 10 fm Hz(-1/2) and a position resolution that is 36 times the quantum limit.