Charge State Conversion, Dynamics, and Single Photon Emission from Diamond using High Voltage Nanosecond Pulse Discharge

单光子发射（SPE）在量子通信和量子信息处理中具有重要意义。虽然在过去的20年里，人们对钻石的SPE进行了广泛的研究，但这些研究大多是全光的（使用外部脉冲激光器），而对其电光或光电效应（不包括微波激发）的研究相对较少。为了在量子通信和量子信息处理的实际系统中利用这些量子发射器，可能需要某种形式的基于电子的调制。本课题利用高电压纳秒脉冲（5kV和50nsec）控制这些缺陷的电荷状态，为实际量子通信系统的设计开辟了新的参数。例如，调制单个量子发射器的发射波长的能力可以为这些量子发射器的光学读出和量子信息编码提供重要的能力。此外，从钻石中产生高效的电驱动发光存在几个关键困难，这极大地限制了它们在实际应用中的潜在用途。这些挑战包括由于与这些宽禁带半导体相关的大肖特基势垒而难以注入载流子。本项目探讨了克服这些挑战的几种策略。一旦克服了这些挑战，金刚石pn结可能为产生电驱动的单光子提供一个很好的平台。本项目将探索利用高电压纳秒脉冲（5kV和50nsec）从金刚石中发射光的新机制。这种方法可以选择性地产生金刚石中硅空位缺陷的负电荷态（即SiV -）的发射，其在738 nm处表现出窄发射（室温下FWHM = 4 nm），与发射约946 nm的电荷中性态（即SiV0）不同。该项目探索比以前研究的更低的缺陷密度（即单缺陷发射），测量电荷-自旋耦合（通过ODMR），寿命和动力学，以及时间相关单光子计数（TCSPC）测量。该项目还将探索从金刚石pn结、耦合到光子晶体腔和波导的电致发光，并将这些器件缩小到更小的尺寸，在更低的电压下工作。高电压纳秒脉冲放电可以在加热可以忽略不计的情况下实现极高的峰值场，为操纵这个研究得很好的量子发射器提供了额外的自由度。虽然通过磁共振激发（即电子自旋共振和ODMR）可以很容易地获得自旋态的操纵，但电荷态操纵尚未建立，并且缺乏操纵这一重要量子数的技术。通过在广泛的金刚石衬底和电压脉冲参数上系统地映射这些器件的发光，可以开发对经典和量子光发射的基本理解，以便回答有关这种电压诱导的电荷状态调制和金刚石中si空位缺陷发射的几个开放问题。该项目将为从小学到高中的各个年级的学生提供量子信息科学教育。此外，将为新的纳米科学课程开发一个专门用于纳米尺度经典和量子光电子学的模块，并且在此资助下的研究成果将在课堂上讨论并整合到课程中。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。

Single photon emission (SPE) is important for quantum communication and quantum information processing. While SPE from diamond has been studied extensively over the past 20 years, most of these studies have been all-optical (using external pulsed lasers), and there have been relatively few on their electro-optic or optoelectronic effects (excluding microwave excitation). In order to utilize these quantum emitters in real systems for quantum communication and quantum information processes, some form of electron-based modulation will likely be needed. This project uses high voltage nanosecond pulses (5kV and 50 nsec) to control the charge state of these defects, which opens up new parameters in the design of practical quantum communication systems. For example, the ability to modulate the emission wavelength of a single quantum emitter can provide an important capability in the optical read-out of these quantum emitters and for encoding quantum information. Also, there are several key difficulties in producing efficient electrically-driven light emission from diamond, which have greatly limited their potential use in practical applications. These challenges include difficulty injecting charge carriers due to the large Schottky barrier associated with these wide bandgap semiconductors. This project explores several strategies for overcoming these challenges. Once these challenges have been overcome, diamond pn-junctions may provide a good platform for producing electrically-driven single photons.This project will explore novel mechanisms of light emission from diamond using high voltage nanosecond pulses (5kV and 50 nsec). This approach can selectively produce emission from the negatively charged state of silicon-vacancy defects in diamond (i.e., SiV–), which exhibits narrow (FWHM = 4 nm at room temperature) emission at 738 nm, as distinct from the charge neutral state (i.e., SiV0) which emits around 946 nm. This project explores lower defect densities (i.e., single defect emission) than were previously studied, measuring charge-spin coupling (via ODMR), lifetimes and dynamics, and time-correlated single photon counting (TCSPC) measurements. The project will also explore electroluminescence from diamond pn-junctions, coupling to photonic crystal cavities and waveguides, and scaling these devices down to smaller sizes that operate at lower voltages. High voltage nanosecond pulse discharges enable extremely high peak fields to be achieved with negligible heating, providing an additional degree of freedom in the manipulation of this well-studied quantum emitter. While manipulation of spin states can be attained easily through magnetic resonance excitation (i.e., electron spin resonance and ODMR), charge state manipulation is not well-established, and techniques for manipulating this important quantum number are lacking. By mapping the luminescence of these devices systematically over a wide range of diamond substrates and voltage pulse parameters, a fundamental understanding of both classical and quantum light emission can be developed, in order to answer several open questions regarding this voltage-induced modulation of the charge state and the emission of Si-vacancy defects in diamond. The project will provide quantum information science education at various grade levels from elementary school to high school students. In addition, a module devoted to nanoscale classical and quantum optoelectronics will be developed for a new nanoscience course, and the research accomplishments under this grant will be discussed in class and integrated into the curriculum.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.