论文标题
使用陷阱集成的超导光子检测器对捕获的离子量子量子的状态读数
State Readout of a Trapped Ion Qubit Using a Trap-Integrated Superconducting Photon Detector
论文作者
论文摘要
我们报告使用陷阱积聚的光子检测器对被困的离子量子标准的高保真状态读数。我们通过用超导纳米导体的单电器探测器（SNSPD）计数状态依赖性的离子荧光光光子来确定单个$^9 $ be $^+$ ion的超细量子状态。平均读数保真度为0.9991（1），平均读数持续时间为46 $μ$ S，并且受读取激光束的极化杂质和非谐振光学泵送的限制。由于离子和检测器之间没有中间的光学元素，因此我们可以将离子荧光用作自校准的光子源来确定检测器量子效率及其对光子入射角和极化的依赖性。
We report high-fidelity state readout of a trapped ion qubit using a trap-integrated photon detector. We determine the hyperfine qubit state of a single $^9$Be$^+$ ion held in a surface-electrode rf ion trap by counting state-dependent ion fluorescence photons with a superconducting nanowire single-photon detector (SNSPD) fabricated into the trap structure. The average readout fidelity is 0.9991(1), with a mean readout duration of 46 $μ$s, and is limited by the polarization impurity of the readout laser beam and by off-resonant optical pumping. Because there are no intervening optical elements between the ion and the detector, we can use the ion fluorescence as a self-calibrated photon source to determine the detector quantum efficiency and its dependence on photon incidence angle and polarization.
