Atomic scale electronics using isoelectronic centers

量子点(QD)彻底改变了我们对半导体材料中载流子的能量和行为的控制程度。然而，由于组成它们的原子数量很多(从1000到100,000)，几乎不可能制造出两个完全相同的量子点，甚至是一个完全具有所需特性的量子点。不幸的是，这个关键问题一直在阻碍一些涉及量子点的最令人兴奋的提议的实现，从更高效的激光到强大的量子计算机。 作为由数万个原子组成的量子点的替代方案，我们建议使用由一个、两个或任何少量等电子陷阱组成的等电子中心(IC)在半导体材料中实现原子尺度的新的电子功能。这一计划的独创性源于这样一个事实：IC在一个系统中结合了许多仅在晶体缺陷(如单原子杂质或量子点)中才有的重要优势：IC可以由大量杂质和主体材料制成，其发射能量和其他特性是广泛可调的，它们表现出低的非均匀展宽，并且它们具有完美定义的对称性。在这项研究计划中，我们建议1)发展对这种鲜为人知的纳米结构行为的物理支配，2)利用其独特的特性应用于许多应用，例如，产生纠缠光子和实现具有增强相干时间的单自旋记忆。 集成电路的研究有可能在许多以前设想的传统量子点和其他纳米结构领域开辟机会。更重要的是，集成电路可以为原子大小的电子产品的发展提供必要的基础，这一主题注定会在不久的将来成为一个重要的、非常活跃的研究领域。最后，研究生获得的知识和经验对于从事光谱学、半导体材料、光学设备和其他精密仪器活动的公司具有战略重要性。

Quantum dots (QDs) have revolutionized the amount of control we have over the energy and behavior of charged carriers in semiconductor materials. However, as a result of the large number of atoms composing them (from 1000 to 100,000), it is nearly impossible to fabricate two identical QDs or even a single one with exactly the desired characteristics. Unfortunately, this critical issue has been impeding the realization of some of the most exciting proposals involving QDs, from more efficient lasers to powerful quantum computers. As an alternative to QDs composed of tens of thousands of atoms, we propose using Isoelectronic Centers (ICs) composed of one, two, or any small number of isoelectronic traps to implement novel electronic functionalities at an atomic scale in semiconductor materials. The originality of this program stems from the fact that ICs combine in one system many important advantages that were only available in either crystalline defects like one-atom impurities or QDs: ICs can be made from a large selection of impurities and host materials, their emission energy and other characteristics are broadly tunable, they exhibit low inhomogeneous broadening and they have perfectly defined symmetries. In this research program, we propose to 1) develop a firm understanding of the physics governing the behavior of this little-studied nanostructure and 2) exploit its unique characteristics for a number of applications such as, for example, the generation of entangled photons and the realization of a single spin memory with enhanced coherence time. Research on ICs has the potential to open up opportunities in many areas where conventional quantum dots and other nanostructures were previously envisioned. Even more significantly, ICs can form the necessary building blocks for the development of atomic-sized electronics, a topic destined to become a prominent and very active research field in a near future. Finally, the knowledge and experience acquired by graduate students are of strategic importance for companies with activities involving spectroscopy, semiconductor materials, optical devices and other precision instrumentations.