We demonstrate super-resolution optical sensing of the size of the wave packet of a single trapped ion. Our method extends the well known ground state depletion (GSD) technique to the coherent regime. Here, we use a hollow beam to strongly saturate a coherently driven dipole-forbidden transition around a sub-diffraction limited area at its center and observe state dependent fluorescence. By spatially scanning this laser beam over a single trapped $^{40}\mathrm{Ca}^+$ ion, we are able to measure the wave packet sizes of cooled ions. Using a depletion beam waist of $4.2(1)\,μ$m we reach a spatial resolution which allows us to determine a wave packet size of $39(9)\,$nm for a near ground state cooled ion. This value matches an independently deduced value of $32(2)\,$nm, calculated from resolved sideband spectroscopy measurements. Finally, we discuss the ultimate resolution limits of our adapted GSD imaging technique in view of applications to direct quantum wave packet imaging.
The variance of the position operator is associated with how wide or narrow a wave-packet is, the momentum variance is similarly correlated with the size of a wave-packet in momentum space, and the angular-momentum variance quantifies to what extent a wave-packet is non-spherically symmetric. We examine an interacting three-dimensional trapped Bose-Einstein condensate at the limit of an infinite number of particles, and investigate its position, momentum, and angular-momentum anisotropies. Computing the variances of the three Cartesian components of the position, momentum, and angular-momentum…
Transport, separation, and merging of trapped ion crystals are essential operations for most large-scale quantum computing architectures. In this work, we develop a theoretical framework that describes the dynamics of ions in time-varying potentials with a motional squeeze operator, followed by a motional displacement operator. Using this framework, we develop a new, general protocol for trapped ion transport, separation, and merging. We show that motional squeezing can prepare an ion wave packet to enable transfer from the ground state of one trapping potential to another. The framework and p…
基于强窗口算子技术，提出了一种研究共振行为的新方法--利用波包动力学。该方法的说明和量化的应用程序的天体物理学的重要的例子，低能量$^{12}$ C + $^{12}$ C碰撞。对于这个选定的，潜在的模型测试的情况下，该技术被证明是提供共振能量和宽度与替代方法，如复杂的能量散射矩阵极点搜索和散射相移分析协议。该方法具有更普遍的能力来研究跨学科的共振现象，涉及被潜在口袋暂时捕获的粒子。
We present a method to extract the phase shift of a scattering process using the real-time evolution in the early and intermediate stages of the collision in order to estimate the time delay of a wave packet. This procedure is convenient when using noisy quantum computers for which the asymptotic out-state behavior is unreachable. We demonstrate that the challenging Fourier transforms involved in the state preparation and measurements can be implemented in $1+1$ dimensions with current trapped ion devices and IBM quantum computers. We compare quantum computation of the time delays obtained in …
We employ the Gross-Pitaevskii equation to study acoustic emission generated in a uniform Bose gas by a static impurity. The impurity excites a sound-wave packet, which propagates through the gas. We calculate the shape of this wave packet in the limit of long wave lengths, and argue that it is possible to extract properties of the impurity by observing this shape. We illustrate here this possibility for a Bose gas with a trapped impurity atom -- an example of a relevant experimental setup. Presented results are general for all one-dimensional systems described by the nonlinear Schrödinger equ…
Doppler-induced tunable and shape-preserving frequency conversion of microwave wave packets
Fondazione Bruno Kessler (FBK)（布鲁诺·克塞勒基金会）；Department of Physics, University of Milano-Bicocca（米兰比可卡大学物理系）；University of Milano-Bicocca（米兰比可卡大学）；Department of Physics, University of Trento（特伦托大学物理系）；University of Trento（特伦托大学）；TIFPA - INFN（INFN理论物理、粒子物理和天体物理研究所）；INFN（意大利国家核物理研究所）；CNR-IFN（意大利国家研究委员会光纤与光子学研究所）；CNR（意大利国家研究委员会）；INFN - Milano Bicocca（INFN米兰比可卡分部）；Pitaevskii BEC Center（皮塔耶夫斯基玻色-爱因斯坦凝聚中心）；CNR-INO（意大利国家研究委员会光学研究所）
Ultralight dark matter detection with trapped-ion interferometry
Walter Burke Institute for Theoretical Physics, California Institute of Technology（加州理工学院沃尔特·伯克理论物理研究所）；Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology（巴塞罗那科学技术高等能源物理研究所）；Institució Catalana de Recerca i Estudis Avançats (ICREA)（加泰罗尼亚高级研究学院）；Department of Physics, King’s College London（伦敦国王学院物理系）；Theoretical Physics Department, CERN（欧洲核子研究中心理论物理部）；Département de Physique Théorique, Université de Genève（日内瓦大学理论物理系）
