CAREER: Fast coherent and incoherent control of atomic ions in scalable platforms

职业：在可扩展平台中对原子离子进行快速相干和非相干控制

• 批准号: 2338897
• 负责人: Karan Mehta
• 金额: $ 55万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2029-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2338897&HistoricalAwards=false
• 关键词: CAREER; Fast; coherent; incoherent; control; CAREER; Fast; coherent; incoherent; control

Individual ions immobilized in vacuum and precisely controlled with lasers constitute a leading platform for quantum computing (QC), simulation, and metrology. Current academic and industrial QC systems operating on up to a few tens of qubits are however far from the millions required for fault-tolerant universal QC, as may be required for practically useful quantum advantage. This scaling represents a challenge that will be met only with innovations in the basic physical techniques used for qubit control, and simultaneously the classical hardware interfacing with qubits. The proposed research will invent and experimentally explore physical methods for ion qubit control capable of overcoming fundamental limitations in speed and error of current approaches. Ion qubit control is generally performed with laser fields, typically assumed to be in spatial profiles essentially uniform over the atom's extent due to conventional implementations with free-space laser beams. This imposes serious limitations on a range of basic functionalities, compromising operation speeds, errors achievable, and physical architectures. Chip-integrated hardware platforms that the PI has pioneered facilitate scaling, and furthermore enable practical and stable delivery of tailored spatial field profiles, where fine spatial variations of the field profile can play a critical role in dynamics. The present work will explore new atom-light interactions enabled in these configurations, thereby opening a new frontier for quantum control in scalable atomic systems. The research immerses PhD and undergraduate researchers in ideas drawing deeply from both classical optics/photonics and quantum science, an intersection of broad and growing importance both in research and for industry workforce. Outreach involving active participation by local middle and high school students is planned. The proposed work explores how structured light fields can address the fundamental challenges in scaling trapped-ion quantum systems -- how can we reduce limiting operation times for both incoherent (laser cooling, readout) and coherent (quantum logic) operations, while further reducing limiting infidelities? Since this work leverages scalable hardware platforms and foundry-fabricated devices to address these questions, achieved advances will directly impact practical large-scale systems in development. Furthermore, the techniques pursued here will inform efforts in precision metrology and searches for new physics based on atomic spectroscopy, in which the PI is also actively involved in collaborations internationally. Key to the concepts proposed are the ability to tailor spatially structured light fields at the atom location with electric field gradients or curvatures along desired directions, but at nulls in the electric field and thus intensify itself. This allows for driving sideband transitions that couple to ion motion with suppressed off-resonant carrier excitation, or driving of particular desired electric quadrupole or octupole transitions with minimal off-resonant couplings. Integrated photonic delivery offers a route to design such delivered beams with high precision, and furthermore deliver the spatially varying profiles to atomic ions with the few nm-level stability required for realization of these concepts. Specific aims within this program include realization of Doppler laser cooling of ion motion 50x faster than current methods allow, fast and broadband cooling to the quantum ground state in novel proposed schemes utilizing tailored optical field profiles, probing of optical quadrupole transitions in higher-order Hermite-Gauss modes, and pursuit of integrated realization of multi-qubit logic with 10^-4 level error, all within a scalable optical platform.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

固定在真空中并精确控制激光的个体离子构成了量子计算（QC），仿真和计量学的领先平台。但是，当前运行多达几十吨的学术和工业QC系统与实际上有用的量子优势所必需的易于故障的通用质量控制所需的数百万量子位相距甚远。这种缩放代表了一个挑战，只有用于量子控制的基本物理技术中的创新以及与Qubits的经典硬件接口。拟议的研究将发明和实验探索能够克服当前方法速度和误差基本限制的离子量子控制的物理方法。通常使用激光场进行离子Qubit控制，通常假定由于具有自由空间激光束的常规实现，在原子范围内基本上是在空间剖面中进行的。这对一系列基本功能，损害操作速度，可实现的错误和物理体系结构施加了严重的限制。 PI开创性的CHIP集成硬件平台有助于扩展，并且还可以实现量身定制的空间田间概况的实用，稳定的交付，在该轮廓上，现场概况的良好空间变化可以在动态中起关键作用。目前的工作将探索在这些配置中启用的新的原子 - 光相互作用，从而打开了可扩展原子系统中量子控制的新边界。该研究将博士和本科研究人员融入了从古典光学/光子学和量子科学的深度汲取的思想中，这在研究和行业劳动力中都广泛而越来越重要。计划涉及当地中学生和高中生积极参与的外展活动。拟议的工作探讨了结构化的光场如何应对缩放被困的离子量子系统的基本挑战 - 我们如何减少不连贯的限制操作时间（激光冷却，读取）和连贯的（量子逻辑）操作，同时进一步降低限制限制性的不足？由于这项工作利用可扩展的硬件平台和制造设备来解决这些问题，因此实现的进步将直接影响开发中实用的大规模系统。此外，这里所追求的技术将为精确计量学方面的努力提供依据，并基于原子光谱搜索新物理学，其中PI在国际上也积极参与合作。提出的概念的关键是能够在原子位置量身定制空间结构的光场，并沿所需的方向使用电场梯度或曲率，但在电场中的nulls中，从而加剧了本身。这允许驾驶边带转变，使离子运动与受抑制的抗抗载体激发，或以最小的非谐振耦合的方式驾驶特定所需的电动四极杆或八杆旋转过渡。集成的光子传递提供了一条以高精度设计这样的传递光束的途径，此外，将空间变化的曲线传递给原子离子，并具有实现这些概念所需的几个NM级稳定性。 Specific aims within this program include realization of Doppler laser cooling of ion motion 50x faster than current methods allow, fast and broadband cooling to the quantum ground state in novel proposed schemes utilizing tailored optical field profiles, probing of optical quadrupole transitions in higher-order Hermite-Gauss modes, and pursuit of integrated realization of multi-qubit logic with 10^-4 level error, all within a scalable光学平台。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来评估值得支持。