Defect States of Silicon Allotropes for Quantum Information Science

非技术描述：该项目专注于新型硅的设计、合成和结构-性能控制，这种新型硅在晶体结构上与微电子技术中使用的传统硅不同。它们正被作为量子信息科学的潜在颠覆性材料进行研究。要研究的新结构由硅笼的三维网络和硅隧道的二维网络组成，这些网络具有将掺杂原子捕获到精确位置的独特能力，从而最大限度地减少与硅晶格的相互作用。被捕获的原子可以充当量子比特，这是存储量子信息的基本元素。这些材料可以克服传统硅面临的主要障碍，比如光学耦合方面的挑战，以及由于量子比特与硅晶格的相互作用导致的信号衰减。因此，该项目可以实现光学效率高的硅基设备，这是硅界的圣杯。这项研究提供了一种新型材料，将给包括计算机芯片、激光、探测器和电信在内的几个全球技术领域带来革命性的变化，从而使社会受益。该项目包括强有力和新颖的教育和外联活动，为K-12学生、本科生和研究生以及STEM中代表性不足的群体提供令人兴奋的机会，包括暑期讲习班和实习、本科生研究经验和社区外联。该项目专注于量子计算和相关应用的材料开发，这是吸引新学生进入STEM的难得机会，为广泛的学生及其教师(小学、初中、高中)，包括丹佛市代表性不足和低收入社区，创新地设计了新的动手、可输出的活动。这些活动被设计为混合活动和面对面活动。模块还专门针对落基山诵读困难症训练营，面向所有级别的学生。技术描述：该项目的重点是促进量子信息科学材料所需的自旋缺陷态的临界性质和控制方面的知识。新型晶硅同素异形体的固有结构和性质为掺杂剂/量子比特提供了精确的间隙位置，同时具有对热激发的低敏感性、长自旋寿命和退相干时间，以及在电信波长内的直接带隙。该项目提供了对自旋缺陷的新理解，研究活动可能导致一类全新的量子信息科学材料。该项目的目标是设计、合成和控制具有间隙掺杂(在笼子或沟道内)、具有比钻石硅更低的热激发和自旋弛豫敏感性的受控缺陷自旋态的晶态硅同素异形体的结构-性能，以缓解用于革命性量子信息科学材料的金刚石硅中的关键问题。该项目的范围包括不同晶体结构、不同掺杂类型和不同浓度/位置的硅同素异形体的薄膜合成和设计，以使系统研究能够了解和控制掺杂的间隙自旋缺陷状态以及结构、光学、电学和量子性质的关系。该项目的方针和方法包括：(1)合成和设计薄膜，以制备具有所需掺杂的高相纯同素异形体；(2)研究薄膜的结构(X射线衍射；共焦拉曼；扫描电子显微镜；飞行时间二次电离质谱仪)、光学(光致发光光谱、吸收)和电学(电导和迁移率)性质关系；(3)利用连续波电子顺磁共振和核磁共振光谱测量自旋-缺陷态；(4)自旋相干的脉冲电子顺磁共振研究。由于研究团队在硅同素异形体合成/性质、基本缺陷/掺杂剂科学和基于固态掺杂剂的量子信息科学方法方面的独特专业知识，该项目能够取得革命性的发现。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical description: The project is focused on the design, synthesis, and structure-properties control of novel forms of silicon, which differ in crystal structure from the conventional silicon used in microelectronic technology. They are being investigated as potentially disruptive materials for quantum information science. The novel structures to be investigated are comprised of 3-dimensional networks of silicon cages and 2-dimensional networks of silicon tunnels that have the unique ability to trap dopant atoms in precise site locations that minimize interaction with the silicon crystalline lattice. The trapped atoms can act as qubits, the basic element for storing quantum information. These materials could overcome major hurdles being faced with conventional silicon, like challenges with optical coupling and decay of signal due to interactions of qubits with the silicon lattice. Hence, the project could enable optically efficient silicon-based devices, a holy grail of the silicon community. This research benefits society by providing a new class of materials that would revolutionize several global technological fields including computer chips, lasers, detectors, and telecommunications. The project includes strong and novel education and outreach activities that provide exciting opportunities for K-12 students, undergraduate and graduate students, and underrepresented groups in STEM, including summer workshops and internships, research experiences for undergraduates, and community outreach. With the project focus on materials development for quantum computing and related applications this is an exceptional opportunity to attract new students to STEM, with innovative design of new hands-on, exportable, activities for a broad range of students and their teachers (elementary, middle, high school), including underrepresented and low income communities in Denver. These activities are designed as both hybrid and in-person. Modules also specifically target the Rocky Mountain Dyslexic Camp for students at all levels. Technical description: The project is focused on advancing the knowledge on critical properties and controls of spin-defect states that are needed for quantum information science materials. The inherent structure and properties of novel crystalline silicon allotropes provides precise interstitial sites for dopants/qubits to sit, along with the potential for low sensitivity to thermal excitation and long spin lifetimes and decoherence times, coupled with a direct bandgap within the telecommunications wavelength. The project provides new understanding of spin defects and the research activities could lead to a completely new class of quantum information science materials. The project goals are to design, synthesize, and control the structure-properties of crystalline silicon allotropes with interstitial dopants (inside cages or channels), with controlled defect spin-states with lower sensitivity than diamond Si to thermal excitation and spin relaxation, to mitigate key issues in diamond silicon for revolutionary quantum information science materials. The project scope includes thin film synthesis and design of silicon allotropes with different crystal structures and dopant types and concentrations/site occupation to enable systematic investigations to understand and control the interstitial spin defect states of the dopants and the relations of structure, optical, electrical, and quantum properties. The project approach and methods include: (i) Synthesis and design of thin films to produce high phase purity allotropes with desired dopants; (ii) Investigation of the structural (X-ray diffraction; confocal Raman; scanning electron microscopy; time of flight secondary ionization mass spectrometry), optical (photoluminescence spectroscopy, absorption), and electrical (conductivity and mobility) property-relations; (iii) Measurement of spin-defect states using continuous-wave electron paramagnetic resonance and nuclear magnetic resonance spectroscopy; (iv) Pulsed electron paramagnetic resonance study of spin coherence. Revolutionary discoveries from this project are possible because of the research team’s unique expertise in silicon allotrope synthesis/properties, in fundamental defect/dopant science and in solid-state dopant-based quantum information science approaches.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.