Donor Electron Spins in Direct Bandgap Semiconductors for Quantum Networks

用于量子网络的直接带隙半导体中的供体电子自旋

• 批准号: 1820614
• 负责人: Kai-Mei Fu
• 金额: $ 38万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1820614&HistoricalAwards=false
• 关键词: Donor; Electron; Spins; Direct; Bandgap

Quantum information networks are expected to enable breakthroughs in computation for optimization problems, encryption-breaking, and materials simulation, as well as realize fundamentally secure communication. Quantum defects in crystals have been shown to exhibit some of the characteristics needed to realize a scalable quantum network; however finding a system that simultaneously exhibits all of the requisite optical and quantum properties remains challenging. Based on promising preliminary results, single donor defects in zinc oxide (ZnO) may satisfy these criteria. This project is to demonstrate single ZnO donor creation and detection with complete control and characterization of the donor electron and nucleus. The goal is to determine the outlook of this system for scalable quantum information applications. In addition, the study of single donor impurities in ZnO may lead to new techniques for studying dopants in semiconductors and will train a diverse group of graduate and undergraduate students in quantum optics and nanotechnology, preparing them for careers in national laboratories, industry, and academia.Defect-based quantum information processing is attractive due to the potential for device integration, the possibility of spin-photon transfer, and the long quantum coherence time in high-purity crystals. For defect systems with optical radiation, measurement-based protocols can be utilized to create quantum networks between non-interacting, remotely separated qubits. This project will investigate a defect system with favorable optical properties, i.e. the donor system in ZnO, which has homogeneous optical transitions and near-unity radiative efficiency in the zero phonon line. Prior studies in an ensemble of donors showed the potential for long coherence times of the donor system if isotopically purified ZnO crystal is available. Here, different techniques will be utilized to isolate single donors: growth of single ZnO nanowires with small diameters, and nano-scale masking or focused ion beam etching combined with epitaxial ZnO layers of low donor density. The isolation of single donors will be confirmed by a photon autocorrelation measurement. Optical pumping and microwave pulses for high-fidelity coherent control will be used to study the optical and spin (electron and nuclear) coherence properties of single ZnO donors, testing the suitability of this system as a qubit candidate. Due to the effective mass nature of the donor, it may be possible to generalize the quantum properties found in ZnO to the entire class of donors in direct band gap semiconductors, furthering the impact of this research.This project is jointly funded by the Quantum Information Science (QIS) Program in the Physics Division in the Directorate for Mathematical and Physical Sciences, and the Condensed Matter Physics (CMP) Program in the Division of Materials Science in the Directorate for Mathematical and Physical Sciences, and the Electronics, Photonics and Magnetic Devices (EPMD) Program in the Division of Electrical, Communications and Cyber Systems Division in the Engineering Directorate.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.

量子信息网络有望在优化问题、加密破解和材料模拟计算方面取得突破，并实现从根本上安全的通信。晶体中的量子缺陷已被证明表现出实现可扩展量子网络所需的一些特性；然而，找到一个同时表现出所有必需的光学和量子特性的系统仍然具有挑战性。基于有希望的初步结果，氧化锌 (ZnO) 中的单施主缺陷可能满足这些标准。该项目旨在演示单个 ZnO 供体的创建和检测，以及对供体电子和原子核的完全控制和表征。目标是确定该系统对于可扩展量子信息应用的前景。此外，对 ZnO 中单施主杂质的研究可能会带来研究半导体掺杂剂的新技术，并将在量子光学和纳米技术方面培养多元化的研究生和本科生，为他们在国家实验室、工业界和学术界的职业生涯做好准备基于缺陷的量子信息处理由于器件集成的潜力、自旋光子转移的可能性以及高纯度晶体中的长量子相干时间而具有吸引力。对于具有光辐射的缺陷系统，可以利用基于测量的协议在非相互作用、远程分离的量子位之间创建量子网络。该项目将研究具有良好光学特性的缺陷系统，即 ZnO 中的供体系统，其在零声子线中具有均匀的光学跃迁和接近一致的辐射效率。先前对供体集合的研究表明，如果有同位素纯化的 ZnO 晶体，供体系统就有可能实现较长的相干时间。在这里，将利用不同的技术来隔离单个施主：小直径的单个 ZnO 纳米线的生长，以及纳米级掩模或聚焦离子束蚀刻与低施主密度的外延 ZnO 层相结合。单个供体的隔离将通过光子自相关测量来确认。用于高保真相干控制的光泵浦和微波脉冲将用于研究单个 ZnO 供体的光学和自旋（电子和核）相干特性，测试该系统作为量子位候选者的适用性。 由于施主的有效质量性质，有可能将 ZnO 中发现的量子特性推广到直接带隙半导体中的整个施主类别，从而进一步扩大这项研究的影响。该项目由量子信息联合资助数学和物理科学局物理司的科学（QIS）计划，以及数学和物理科学局材料科学司的凝聚态物理（CMP）计划，以及电子学，工程理事会电气、通信和网络系统部的光子学和磁性器件 (EPMD) 项目。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Ensemble spin relaxation of shallow donor qubits in ZnO

ZnO 中浅施主量子位的系综自旋弛豫

• DOI: 10.1103/physrevb.105.195202
• 发表时间: 2022-05
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Niaouris, Vasileios;Durnev, Mikhail V.;Linpeng, Xiayu;Viitaniemi, Maria L.;Zimmermann, Christian;Vishnuradhan, Aswin;Kozuka, Yusuke;Kawasaki, Masashi;Fu, Kai
• 通讯作者: Fu, Kai

Coherent Spin Preparation of Indium Donor Qubits in Single ZnO Nanowires

单 ZnO 纳米线中铟供体量子位的相干自旋制备

• DOI: 10.1021/acs.nanolett.1c04156
• 发表时间: 2022-03
• 期刊: Nano Letters
• 影响因子: 10.8
• 作者: Viitaniemi, Maria L.;Zimmermann, Christian;Niaouris, Vasileios;D’Ambrosia, Samuel H.;Wang, Xingyi;Kumar, E. Senthil;Mohammadbeigi, Faezeh;Watkins, Simon P.;Fu, Kai
• 通讯作者: Fu, Kai

Coherence Properties of Shallow Donor Qubits in ZnO

ZnO 中浅施主量子位的相干特性

• DOI: 10.1103/physrevapplied.10.064061
• 发表时间: 2018-12
• 期刊: Physical Review Applied
• 影响因子: 4.6
• 作者: Linpeng, Xiayu;Viitaniemi, Maria L.K.;Vishnuradhan, Aswin;Kozuka, Y.;Johnson, Cameron;Kawasaki, M.;Fu, Kai
• 通讯作者: Fu, Kai

Optical spin control and coherence properties of acceptor bound holes in strained GaAs

应变GaAs中受主束缚空穴的光学自旋控制和相干特性

• DOI: 10.1103/physrevb.103.115412
• 发表时间: 2020-12-13
• 期刊: arXiv: Quantum Physics
• 作者: X. Linpeng;T. Karin;M. Durnev;M. Glazov;R. Schott;A. Wieck;A. Ludwig;K. Fu
• 通讯作者: K. Fu