Experimental study of hole spin qubits in gated semiconductor devices for quantum processing and communication applications

用于量子处理和通信应用的门控半导体器件中空穴自旋量子位的实验研究

• 批准号: RGPIN-2019-04089
• 负责人: Studenikin, Sergei
• 金额: $ 2.48万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=737401
• 关键词: Experimental; study; hole; spin; qubits

It is well established that quantum computers will be significantly more powerful for certain computation and optimization tasks and that single photons used as "flying qubits" will provide 100% security against possible eavesdropping attacks. Solid-state spin qubits attract a rapidly growing worldwide interest for developing quantum information and secure communication applications. An isolated electron spin is the most natural two-level system for a quantum bit or a qubit, the basic element of a quantum computer. Semiconductor based spin qubits form the most promising platform from at least the scalability point of view for building many-qubit quantum processors, because semiconductors can naturally adopt all developments of the advanced microelectronics silicon technology. The vast majority of studies to date have been performed on electron spin qubits in different semiconductor materials. In contrast to more studied electron qubits, this proposal is devoted to exploration of hole spin qubits isolated in gated quantum dot devices. Using hole spin qubits represent a new paradigm for emerging quantum information and communication technologies. The absence of an electron in a fully filled semiconductor valence band, i.e. a hole, can be treated as a positive quasiparticle which can move and possess spin. Holes possess a number of attractive properties for spin qubit applications. Specifically, holes have much stronger spin-orbit coupling, which can be used for much faster spin manipulations, and a reduced hyperfine interaction with surrounding nuclear spins for improved quantum coherence. Additionally, the valence band is inherently free from valleys, which is important to avoid unwanted degeneracies of qubit states. The long term goal of my proposal is the exploration of hole spin qubits as a new system platform for quantum computing and secure communications. In the next five years, my research will focus on developing single- and two-spin hole qubits in gated quantum dot devices. Coherence properties of the hole spin qubits will be studied by different experimental methods such as single-hole electric dipole spin resonance (EDSR), Rabi oscillations and Ramsey fringes. An advanced latching protocol pioneered in our group will be used in studies requiring reliable single-shot read-out of spin qubit states. The fundamental knowledge attained in this research program will be published in open-access journals and can be used by other researches and/or by high-tech companies interested in quantum technologies. There is growing interest in quantum technologies worldwide, including in Canada. Consequently, there is a growing demand for highly qualified personnel (HQP) familiar with quantum physics and technologies. The HQP trained in the course of this research will acquire necessary knowledge and practical skills required in the emerging high-tech job market in Canada.

众所周知，量子计算机在某些计算和优化任务中的能力将显著增强，而且用作“飞行量子比特”的单个光子将提供100%的安全性，以抵御可能的窃听攻击。固态自旋量子比特在开发量子信息和保密通信应用方面吸引了全球范围内迅速增长的兴趣。孤立的电子自旋是量子比特或量子比特最自然的二能级系统，量子比特是量子计算机的基本元素。基于半导体的自旋量子比特构成了最有希望的平台，至少从可伸缩性的角度来看，因为半导体可以自然地采用先进的微电子硅技术的所有发展。到目前为止，绝大多数的研究都是在不同的半导体材料中进行的电子自旋量子比特。与更多的电子量子比特研究不同，该提议致力于探索孤立在门控量子点器件中的空穴自旋量子比特。使用空穴自旋量子比特代表了新兴的量子信息和通信技术的新范式。在完全充满的半导体价带中没有电子，即空穴，可以被视为可以运动并具有自旋的正准粒子。对于自旋量子比特的应用，空穴具有许多吸引人的性质。具体地说，空穴具有更强的自旋-轨道耦合，可用于更快的自旋操纵，并减少与周围核自旋的超精细相互作用，以提高量子相干性。此外，价带本质上没有山谷，这对于避免不必要的量子比特态简并非常重要。我提议的长期目标是探索空穴自旋量子比特作为量子计算和保密通信的新系统平台。在接下来的五年里，我的研究将集中在开发门控量子点设备中的单自旋和双自旋洞量子比特。用不同的实验方法，如单空穴电偶极自旋共振(EDSR)、Rabi振荡和Ramsey条纹，研究了空穴自旋量子比特的相干性质。我们团队首创的先进锁存协议将用于需要可靠的单次读出自旋量子比特态的研究。在这项研究计划中获得的基本知识将发表在开放获取的期刊上，并可供其他研究和/或对量子技术感兴趣的高科技公司使用。包括加拿大在内的世界各地对量子技术的兴趣日益浓厚。因此，对熟悉量子物理和技术的高素质人才(HQP)的需求越来越大。在本研究过程中培训的HQP将获得加拿大新兴高科技就业市场所需的必要知识和实践技能。