Scanning Probe and Point Projection Microscopies for Fundamental Nano-Science Studies

用于基础纳米科学研究的扫描探针和点投影显微镜

• 批准号: RGPIN-2014-05684
• 负责人: Wolkow, Robert
• 金额: $ 7.21万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=588559
• 关键词: Scanning; Probe; Point; Projection; Microscopies

Scanning probe microscopes (SPMs) have been extraordinarily effective tools for elucidating properties inherent to the nano-scale. Further development and application of SPMs is central to our overall research program. Our proposed studies will gain further fundamental understanding of surface-confined nano-scale properties of silicon. Concepts like field controlled computing, FCC, a basis for extremely fast and low power classical computing have been transformed by our discovery that silicon dangling bonds (DBs), created by removal of single H atoms from an H-terminated silicon surface, serve as atomic silicon quantum dots. Previous implementations required extreme cryogenic conditions. Coupled DBs make FCC viable at room temperature. The subject of coupled DBs is in its infancy. As pioneers of the concept and due to our facilities, substantial re-tooling, and previous work and collaborations, we are ideally positioned to explore it. Our newly established and highly stable 4 Kelvin SPM (both scanning tunneling microscope, STM, and atomic force microscope, AFM) allows us to enter a new fabrication and measurement regime. An integral field ion microscope allows routine deployment of our nitrogen stabilized single atom tip as a scanned probe. A second 4 K instrument, with magnet, and radio frequency detection capabilities will soon be operational, allowing most ideal ever single spin electron spin resonance measurements. The spectroscopy of single and coupled DBs will inform classical and quantum computing studies. Coulomb blockading effects will become accessible. AFM force scans will provide a new perspective on charge distributions at DBs. Extraordinary new AFM sensors we have developed enhance our chances of success. Experimental study of inter-DB tunneling through current-voltage, IV, spectra, with close coupled models developed with collaborators, will yield strength of interaction (~100 meV at 2 nm separation is expected) critically informing models of information conveyance by DB ensembles. Knowledge of DB coupling strength will guide an extensive joint theoretical and experimental program with Barry Sanders at Calgary that will assess tunnel rate and coherence properties. We predict ~10e5 coherent oscillations may be completed before a decohering event. In collaboration with Hong Guo at McGill, and with a co-supervised student, we will extend our joint studies of surface state mediated transport. We aim to reveal the nature and magnitude of such surface transport channels, thereby settling some controversy, and furthermore expect to indicate the possibility of connecting future nano-devices in this unique way. Our home made multi-probe STM will enable these atom-scale transport studies. DB-based wires, tunnel gaps and single electron transistors of unprecedented uniformity will be explored. With Konrad Walus of UBC, who works with dWAVE, the maker of a quantum annealing computer, we have a unique program of study for FCC circuit optimization. Woven throughout the proposal are refinements and applications of our nano-tips. The tip is fabricated by a chemical and field assisted, spatially restricted etch that leaves all but the apex W atom nitride coated. Unlike coating-free sharp metal tips, ours are extremely robust. A coherent electron emission opening angle of >14 degrees has been achieved, compared to ~3 degrees for any previous source. We calculate that 0.2 nm holographic projection microscope resolution is now possible, compared to 1.5 nm previously. High resolution and low beam damage will allow biological molecules to be imaged. Phase change around nano-magnets will be accessible. Our training record is excellent. Our students will get and will create jobs directly related to this work.

扫描探针显微镜（SPM）已非常有效的工具，阐明固有的纳米尺度的属性。 SPM的进一步开发和应用是我们整个研究计划的核心。我们提出的研究将获得进一步的基本了解的表面限制的纳米尺度的性质的硅。场控计算（FCC）等概念是极快速和低功耗经典计算的基础，我们发现硅悬挂键（DB）是通过从H-终止的硅表面去除单个H原子而产生的，可以用作原子硅量子点。以前的实施需要极端的低温条件。偶联的DBs使FCC在室温下可行。 耦合数据库的研究还处于起步阶段。作为这一概念的先驱，由于我们的设施，大量的重新加工，以及以前的工作和合作，我们处于理想的位置来探索它。我们新建立的高度稳定的4开尔文SPM（扫描隧道显微镜，STM和原子力显微镜，AFM）使我们能够进入一个新的制造和测量制度。积分场离子显微镜允许常规部署我们的氮稳定的单原子尖端作为扫描探针。 第二个4K仪器，具有磁铁和射频检测能力，将很快投入使用，允许最理想的单自旋电子自旋共振测量。 单个和耦合DB的光谱将为经典和量子计算研究提供信息。库仑阻塞效应将变得容易获得。AFM力扫描将提供一个新的角度在DBs的电荷分布。 我们开发的非凡的新AFM传感器提高了我们成功的机会。 通过电流-电压，IV，光谱，与合作者开发的紧密耦合模型的DB间隧穿的实验研究，将产生相互作用的强度（在2 nm的分离约100 meV预计），严格通知DB系综的信息传输模型。DB耦合强度的知识将指导一个广泛的联合理论和实验计划与巴里桑德斯在卡尔加里，将评估隧道速率和相干特性。 我们预测~ 10 e5相干振荡可能在一个散肩事件之前完成。与麦吉尔大学的郭红合作，并与一名共同监督的学生合作，我们将扩展我们对表面状态介导运输的联合研究。我们的目标是揭示这种表面传输通道的性质和大小，从而解决一些争议，并进一步期望表明以这种独特的方式连接未来纳米器件的可能性。我们自制的多探针STM将使这些原子尺度的输运研究。将探索前所未有的均匀性的DB基导线、隧道间隙和单电子晶体管。 UBC的Konrad Walus与量子退火计算机制造商dWAVE合作，我们有一个独特的FCC电路优化研究计划。 在整个提案中编织的是我们的纳米尖端的改进和应用。尖端是由化学和场辅助，空间限制蚀刻，留下所有，但顶点W原子氮化物涂层。与无涂层的锋利金属刀头不同，我们的刀头非常坚固。已经实现了>14度的相干电子发射开度角，相比之下，对于任何先前的源为~3度。我们计算出，0.2 nm的全息投影显微镜分辨率现在是可能的，相比以前的1.5 nm。 高分辨率和低光束损伤将允许生物分子成像。纳米磁体周围的相变将是可访问的。 我们的训练记录非常好。 我们的学生将获得并将创造与这项工作直接相关的工作。