Electrically-driven silicon single-photon source

量子光源是量子信息处理、通信、传感和成像的推动者。进一步的进展需要电驱动（即电触发）的单光子源，以低损耗的电信波长发射，并且可以小型化并与硅电子电路集成。这个项目的目的是试点这种单光子源的发展，目前还没有。这一努力的成功将代表着该领域前所未有的进步，并将有助于推动量子信息技术的边界，这反过来又可能导致我们在量子领域推进光学和材料科学的能力的扩展。通过这样做，提议的努力也将促进我们的工程教育和培训计划在量子技术方面的变革进步，从而不仅影响博士后、研究生和本科生的培训。提出的努力利用了先前的突破极限的努力，在电信o波段（~1.3 μm）产生明亮的受激辐射，来自具有周期性分布的g中心的晶体硅-也称为碳硅“色中心”。这个项目也将突破边界，但会达到相反的极限——即电抽运单光子发射，这在硅和单色（零声子）中是前所未有的。通过创新的Si晶体纳米图案和纳米级孔的二维周期性阵列，它将在纳米孔的侧壁中嵌入周期性分布的g中心，并且该纳米孔的机械应变和带隙也降低了。正如我们在之前的报告中所展示的那样，这将允许人们在几乎不增加总体光损失的情况下创建发射g中心，同时将注入的载流子引导到g中心进行重组和发射。此外，周期性图案将被设计成这样一种方式，即自发发射率可以通过珀塞尔效应增强。这将通过设计纳米孔阵列的结构和周期性来实现，以创建具有小模式体积和高密度光子态的光子晶体，并在g中心发射频率/附近达到峰值。在允许电子隧穿的同时，用一层薄薄的阻挡层阻挡漏孔电流，可以实现额外的增强。采用多孔低折射率硅层和透明电极，设计横向阻挡带和垂直发射锥的光子晶体结构（纳米孔阵列），可以最大限度地提高光子收集效率。顶部的电极，也将被设计成宏观尺寸的阵列，将允许选择性地泵送单个SPS区域，从而允许选择最亮、单色且仍然满足单光子标准的单光子发射器。这些措施有望为我们提供第一个在电信o波段的阵列、电泵浦、单色硅单光子源，这些源与用于量子信息处理的硅电子兼容并准备集成。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Quantum light sources are enablers of quantum information processing, communications, sensing and imaging. Further progress demands single-photon sources that are electrically-driven (i.e. electrically triggered), emit at a low-loss telecom wavelength, and can be miniaturized and integrated with silicon electronic circuits. This project aims to pilot the development of such single-photon sources that are not yet available. Success in this endeavor would represent an unprecedented advance in the field and would helppush the boundaries of quantum information technology, which in turn could lead to expansion of our capabilities in advancing optical and materials sciences in the quantum domain. In so doing, the proposed effort will also catalyze transformative advances of our engineering education and training programs towards quantum technologies, thereby not only impacting the training of postdocs, graduates, and undergraduates.The proposed effort leverages a prior limit-breaking effort in generating bright stimulated emission in the telecom O-band (~1.3 μm) from a crystalline silicon patterned with periodically distributed G-centers – also known as the carbon-silicon ‘color-center’. This project too will push the boundary, but to the opposite limit – i.e. to electrically-pumped single-photon emission, which is unprecedented in silicon and monochromatic (zero-phonon). Enabled by the innovative nanopatterning of a Si crystal with a 2D periodic array of nanoscale holes, it would create a periodic distribution of G-centers embedded in the sidewall of the nanohole which is also mechanically strained and bandgap lowered. As demonstrated in our earlier reports, this would allow one to create the emissive G-centers with little increase in the overall optical loss while simultaneously channeling the injected charge carriers to the G-centers for recombination and emission. Furthermore, the periodic patterning will be designed in such a way that the spontaneous emission rate can be enhanced via the Purcell effect. This will be achieved by engineering the structure and periodicity of the nano-hole array to create a photonic crystal with a small mode volume and a high density of photon states to peak at/near the frequency of the G-center emission. An extra enhancement can be achieved by blocking the leakage hole current with a thin barrier layer while still allowing electrons to tunnel through. The photon collection efficiency will be maximized with both the holey low-index silicon layer and the transparent electrode as well as the design of the photonic crystal structure (nanohole array) with the stop band in the lateral direction and the emission cone in the perpendicular direction. The top electrodes, also to be patterned into an array of macroscopic sizes, would allow selective pumping of individual SPS zones so as to allow selection of single-photon emitters that are brightest, monochromatic and yet still satisfy the single-photon criterion. These measures are expected to provide us the first-ever, arrayed, electrically-pumped, monochromatic silicon single-photon sources in the telecom O-band that are compatible to and ready for integration with silicon electronics for quantum information processing.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.