Cavity-QED with multi-species ion crystals

提出的PHD项目的目的是研究在基于腔的量子处理器之间的光子链路的实现中使用两种物种的离子晶体。在该项目的第一部分，锶离子将被用作制冷剂，以使共捕获的钙离子和腔光子之间能够连续、高速率地产生纠缠。不需要激光冷却钙离子将在不影响保真度的情况下增加纠缠率。该项目的第二阶段将包括在产生离子-光子纠缠之前连续在两个物种之间进行量子态转移。这里的重点将集中在离子-光子纠缠态的转移，从最初用于通过腔辅助跃迁产生纠缠的钙离子到共捕获的锶离子。为此，现有的离子-腔系统将扩展到同时适用于两种离子，并将使用QCS中心资助的锶和钙离子激光系统。该项目将与牛津大学的大卫·卢卡斯小组合作进行，该小组在处理两种离子晶体方面有经验。这位博士生将在牛津大学度过一段时间，向大卫的团队学习，并将一些技术诀窍转移到苏塞克斯1号。该项目将如何为中心的目标做出贡献：该项目将有助于实现可交付成果1.9。正如量子技术中心计划的第一阶段所确定的那样，离子腔系统是实现完全可扩展的量子计算机的关键，该博士项目将有助于提供这种可扩展的技术并展示其功能。将其扩展到两个离子物种的操作是朝着基于离子的量子计算机的实际实施迈出的重要一步。学生资格将如何与项目中任何计划的QCS人员匹配：该学生将由Keller教授指导，并将与Graham Stutter博士(QCS Hub资助的博士后)和现有的高级博士生一起工作。该项目将如何与更广泛的QCS计划相适应--学生是否有机会与其他小组和合作机构合作：虽然主要工作设在苏塞克斯，但在项目的初始阶段，与牛津大学离子捕获小组的频繁讨论有望利用他们在处理两种离子晶体方面的专业知识。为了充分利用这一点，学生将在牛津大学的小组中花时间学习如何使用两种离子晶体。培训：学生将在项目中使用什么设施/仪器，将提供什么培训，由谁提供：设施：苏塞克斯小组提供一个功能齐全的离子陷阱系统，配备两个物种实验所需的所有激光。培训：学生将进入苏塞克斯博士学院，该学院提供一般研究技能、可转移技能和商业化培训(通过苏塞克斯创新中心)。此外，学生将通过我们的教学模块和Qt中心活动接受QIP和Qt方面的培训。主要的培训将通过他们的实验室工作，在那里学生将接受离子陷阱技术、捕获离子的激光控制、电子学、光学和真空技术的培训。凯勒教授和他的研究团队将提供这种培训。你将如何确保有一个多样化的学生申请者池：一个性别平衡的小组将进行博士生招聘，广告将接受性别偏见检查。要求所有工作人员接受招聘、平等和多样性方面的培训。特别是，在面试小组招聘时，需要对所有工作人员进行无意识偏见方面的培训。总的来说，苏塞克斯数学和物理科学学院致力于在招生过程的每一步促进多样性和平等。

The aim of the proposed PhD project is to investigate the use of two-species ion crystals in the cavity-based implementation of the photonic link between quantum processors. In the first part of the project, strontium ions will be employed as a refrigerant to enable the continuous, high-rate generation of entanglement between a co-trapped calcium ion and cavity photons. Removing the need for laser cooling of the calcium ion will increase the entanglement rate without compromising the fidelity. The second stage of the project will then include quantum state transfer between the two species consecutive to the generation of ion-photon entanglement. Here the focus will be on the transfer of the ion-photon entangled state from the calcium ion, initially used to generate the entanglement via a cavity-assisted transition, to the co-trapped strontium ion.To this end, an existing ion-cavity system will be extended to operate with both ion species and the QCS Hub-funded laser systems for strontium and calcium ions will be used.The project will be pursued in collaboration with the group of David Lucas at Oxford, which has experience in working with two-species ion crystals. The PhD student will spend some time at Oxford to learn from David's team and transfer some of the know-how to Sussex.1. How the project would contribute to the Hubs' goals: The project will contribute to achieving Deliverable 1.9. As identified in the first phase of the Quantum Technology Hub Programme, ion-cavity systems are essential to achieve a fully scalable quantum computer and this PhD project will help to deliver such a scalable technology and demonstrate its functionality. Extending this to a two-ion species operation is a significant step towards a practical implementation of an ion-based quantum computer.2. How the studentship would fit in with any planned QCS staffing on the project: The student will be supervised by Prof Keller and will work with Dr Graham Stutter (QCS Hub funded postdoc) and existing senior PhD students.3. How the project would fit in with the wider QCS programme - would there be opportunities for students to work in collaboration with other groups and partner institutions: While the main work is based in Sussex, during the initial phase of the project frequent discussions with the ion-trapping group at Oxford are expected to take advantage of their expertise in working with two-species ion crystals. To make full use of this, the student will spend time in the group at Oxford to learn how to work with two-species ion crystals.4. What facilities / apparatus would be available for the student to use in the project, what training would be provided and by whom: Facilities: The Sussex group provides a fully functioning ion trap system with all lasers that are required for the two-species experiment.Training: The student will join the Sussex Doctoral School, which provides training in general research skills, transferable skills and commercialisation training (through the Sussex Innovation Centre). In addition, the student will receive training in QIP and QT through our taught modules and QT hub activities. The main training will be through their laboratory work where the student will receive training in ion trap technology, laser control of trapped ions, electronics, optics and vacuum technology. Prof Keller and his research team will deliver this training.5. How you will ensure there is a diverse pool of applicants for the studentship: A gender-balanced panel will conduct the PhD student recruitment and the advertisement will be checked for gender bias. All staff is required to be trained in recruitment, and equality and diversity. In particular, training in unconscious bias is required for all staff on recruitment in interview panels. In general, the Sussex School for Mathematical and Physical sciences is committed to promote diversity and equality at every step in the recruitment process