Leopold T, King S A, Micke P, Bautista-Salvador A, Heip J C, Ospelkaus C, Crespo López-Urrutia J R, Schmidt P O
Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
Rev Sci Instrum. 2019 Jul;90(7):073201. doi: 10.1063/1.5100594.
A cryogenic radio-frequency ion trap system designed for quantum logic spectroscopy of highly charged ions (HCI) is presented. It includes a segmented linear Paul trap, an in-vacuum imaging lens, and a helical resonator. We demonstrate ground state cooling of all three modes of motion of a single Be ion and determine their heating rates as well as excess axial micromotion. The trap shows one of the lowest levels of electric field noise published to date. We investigate the magnetic-field noise suppression in cryogenic shields made from segmented copper, the resulting magnetic field stability at the ion position and the resulting coherence time. Using this trap in conjunction with an electron beam ion trap and a deceleration beamline, we have been able to trap single highly charged Ar (Ar XIV) ions concurrently with single Be ions, a key prerequisite for the first quantum logic spectroscopy of a HCI. This major stepping stone allows us to push highly-charged-ion spectroscopic precision from the gigahertz to the hertz level and below.
本文介绍了一种用于高电荷离子（HCI）量子逻辑光谱学的低温射频离子阱系统。它包括一个分段线性保罗阱、一个真空成像透镜和一个螺旋谐振器。我们展示了单个铍离子三种运动模式的基态冷却，并确定了它们的加热速率以及额外的轴向微运动。该阱显示出迄今为止公布的最低水平的电场噪声之一。我们研究了由分段铜制成的低温屏蔽中的磁场噪声抑制、离子位置处的磁场稳定性以及由此产生的相干时间。将这个阱与电子束离子阱和减速束线结合使用，我们已经能够同时捕获单个高电荷氩离子（Ar XIV）和单个铍离子，这是首次对高电荷离子进行量子逻辑光谱学的关键前提。这一重要的里程碑使我们能够将高电荷离子光谱学精度从千兆赫兹级别提升到赫兹级别及以下。
