利用激光冷却和量子逻辑方法的冷却和检测方案可以有助于重子扇区中的高精度CPT对称性测试。本文介绍了一个利用库仑相互作用对$^9$ Be $^+$离子进行共振冷却的实验。我们设计并建立了一个装置，首次在潘宁阱中显示了两个相同离子之间的这种耦合。在本文中，我们提出了成功的装载和多普勒冷却的云和单离子的证据。我们的耦合方案在一系列高精度测量中的应用在潘宁陷阱，并有可能大大提高这些实验中的运动控制。
英文摘要：
Cooling and detection schemes using laser cooling and methods of quantum logic can contribute to high precision CPT symmetry tests in the baryonic sector. This work introduces an experiment to sympathetically cool protons and antiprotons using the Coulomb interaction with a $^9$Be$^+$ ion trapped in a nearby but separate potential well. We have designed and set up an apparatus to show such coupling between two identical ions for the first time in a Penning trap. In this paper, we present evidence for successful loading and Doppler cooling of clouds and single ions. Our coupling scheme has applications in a range of high-precision measurements in Penning traps and has the potential to substantially improve motional control in these experiments.
In Penning traps electromagnetic forces are used to confine charged particles under well-controlled conditions for virtually unlimited time. Sensitive detection methods have been developed to allow observation of single stored ions. Various cooling methods can be employed to reduce the energy of the trapped particle to nearly at rest. In this review we summarize how highly charged ions offer unique possibilities for precision measurements in Penning traps. Precision atomic and nuclear masses as well as magnetic moments of bound electrons allow among others to determine fundamental constants li…
A Cryogenic Penning Trap Based on Permanent Magnets
Heinrich Heine Universität Düsseldorf（杜塞尔多夫海因里希·海涅大学）；Institut für Physik, Johannes Gutenberg-Universität（美因茨约翰内斯·古腾堡大学物理研究所）；Max-Planck-Institut für Kernphysik（马克斯·普朗克核物理研究所）；GSI Helmholtzzentrum für Schwerionenforschung GmbH（达姆施塔特重离子研究中心）；Institut für Quantenoptik, Leibniz Universität Hannover（汉诺威莱布尼茨大学量子光学研究所）；Physikalisch-Technische Bundesanstalt（德国联邦物理技术研究院）；RIKEN, Fundamental Symmetries Laboratory（理化学研究所基本对称性实验室）；Graduate School of Arts and Sciences, University of Tokyo（东京大学大学院人文社会系研究科）；CERN（欧洲核子研究中心）
Current precision experiments with single (anti)protons to test CPT symmetry progress at a rapid pace, but are complicated by the need to cool particles to sub-thermal energies. We describe a cryogenic Penning-trap setup for $^9$Be$^+$ ions designed to allow coupling of single (anti)protons to laser-cooled atomic ions for sympathetic cooling and quantum logic spectroscopy. We report on trapping and laser cooling of clouds and single $^9$Be$^+$ ions. We discuss prospects for a microfabricated trap to allow coupling of single (anti)protons to laser-cooled $^9$Be$^+$ ions for sympathetic laser co…
We constrain the coupling between axionlike particles (ALPs) and photons, measured with the superconducting resonant detection circuit of a cryogenic Penning trap. By searching the noise spectrum of our fixed-frequency resonant circuit for peaks caused by dark matter ALPs converting into photons in the strong magnetic field of the Penning-trap magnet, we are able to constrain the coupling of ALPs with masses around $2.7906-2.7914\,\textrm{neV/c}^2$ to $g_{aγ}< 1 \times 10^{-11}\,\textrm{GeV}^{-1}$. This is more than one order of magnitude lower than the best laboratory haloscope and approximat…
We report the design and experimental demonstration of a compact, reconfigurable Penning ion trap constructed with rare-earth permanent magnets placed outside of a trap vacuum enclosure. We describe the first observation of Doppler laser cooling of ions in a permanent magnet Penning trap. We detail a method for quantifying and optimizing the trap magnetic field uniformity in situ using a thermal beam of neutral $^{40}$Ca precursor atoms. Doppler laser cooling of $^{40}$Ca$^+$ is carried out at 0.65~T, and side-view images of trapped ion fluorescence show crystalline order for both two- and thr…
First-order perturbative calculation of the frequency-shifts caused by static cylindrically-symmetric electric and magnetic imperfections of a Penning trap
Trapped ions boast long coherence times and excellent gate fidelities, making them a useful platform for quantum information processing. Scaling to larger numbers of ion qubits in RF Paul traps demands great effort. Another technique for trapping ions is via a Penning trap where a 2D crystal of hundreds of ions is formed by controlling the rotation of the ions in the presence of a strong magnetic field. However, the rotation of the ion crystal makes single ion addressability a significant challenge. We propose a protocol that takes advantage of a deformable mirror to introduce AC Stark shift p…
We report microwave spectroscopy of co-trapped $^9\text{Be}^+$ and $^{40}\text{Ca}^+$ within a compact permanent-magnet-based Penning ion trap. The trap is constructed with a reconfigurable array of NdFeB rings providing a 0.654 T magnetic field that is near the 0.6774-T magnetic-field-insensitive hyperfine transition in $^9\text{Be}^+$. Performing Ramsey spectroscopy on this hyperfine transition, we demonstrate nuclear spin coherence with a contrast decay time of >1 s. The $^9\text{Be}^+$ is sympathetically cooled by a Coulomb crystal of $^{40}\text{Ca}^+$, which minimizes $^9\text{Be}^+$ ill…
We demonstrate phase locking of two ultraviolet laser sources by modulating a fundamental infrared laser with 4th-order sidebands using an electro-optic modulator and phase locking of one sideband to a second fundamental infrared laser. Subsequent sum frequency generation and second harmonic generation successfully translates the frequency offset to the ultraviolet domain. The phase lock at 139 GHz is confirmed through stimulated Raman transitions for thermometry of $^9$Be$^+$ ions confined in a cryogenic Penning trap. This technique might be used for sideband cooling of single $^9$Be$^+$ ions…
Penning collisions of laser-cooled metastable helium atoms
给出了亚稳态氦原子磁光阱中两体损失率的实验结果。通过监测陷阱荧光的衰减，以系统的方式测量范围从-5到-30 MHz和不同强度的几种激光失谐的绝对速率。研究了两体损失率系数$β$对激发态（$2^3P_2$）和亚稳态（$2^3S_1$）粒子数的依赖关系.从这些结果我们推断出一个相当均匀的速率常数$K_{sp}=(1{\pm}0.4)\times10^{-7}$ cm $^3$ /s。
The possibility to apply active feedback to a single ion in a Penning trap using a fully digital system is demonstrated. Previously realized feedback systems rely on analog circuits that are susceptible to environmental fluctuations and long term drifts, as well as being limited to the specific task they were designed for. The presented system is implemented using an FPGA-based platform (STEMlab), offering greater flexibility, higher temporal stability and the possibility for highly dynamic variation of feedback parameters. The system's capabilities were demonstrated by applying feedback to th…
Full Single-Quantum Control of Particles in Penning Traps for Symmetry Tests at the Quantum Limit
Leibniz Universität Hannover（汉诺威莱布尼茨大学）；TU Braunschweig（布伦瑞克工业大学）；Heinrich-Heine-Universität Düsseldorf（杜塞尔多夫海因里希·海涅大学）；RIKEN（理化学研究所）；Physikalisch-Technische Bundesanstalt（德国联邦物理技术研究院）；Universidad de Cádiz（加的斯大学）
We present a theoretical analysis of an electron confined by a Penning trap, also known as geonium, that is affected by gravity. In particular, we investigate the gravitational influence on the electron dynamics and the electromagnetic field of the trap. We consider the special case of a homogeneous gravitational field, which is represented by Rindler spacetime. In this spacetime the Hamiltonian of an electron with anomalous magnetic moment is constructed. Based on this Hamiltonian and the exact solution to Maxwell equations for the field of a Penning trap in Rindler spacetime, we derived the …
