EAGER: Enabling Quantum Leap: Manipulating polariton entanglement for room-temperature quantum logic

量子计算比传统计算提供了巨大的优势，因为它利用了量子力学现象，原则上可以比目前最好的计算机更快、更有效地执行逻辑任务。然而，量子计算仍处于初级阶段。量子计算利用了纠缠--量子粒子的一个关键特性--在这种情况下，根本不可能区分两个完全相同的粒子的性质，无论它们彼此之间有多远。在室温下实现强大的纠缠仍然是实现量子计算机最重要的挑战之一。本项目通过设计和制造光学设备来克服现有的室温纠缠的基本限制，这种光学设备产生被称为极化子的光和物质的混合纠缠粒子。通过在器件上施加电压来操纵和控制纠缠极化子。极化纠缠被设计成在足够长的时间内保持稳定，以便在室温下进行量子计算操作。除了这项研究涉及的科技创新外，它还作为一个培训平台，为美国的智力资本和科学基础设施做出贡献，在美国，量子技术的重要性越来越大。技术描述：该项目的主要目标是展示一种在室温下运行的通用量子门，利用半导体微腔中的极化纠缠，这些微腔被设计为可通过外部电场寻址。激子极化子是半光、半物质的准粒子，由光子和激子的强(非微扰)耦合产生。由于它们的混合身份，激子极化子有望通过操纵物质中的纠缠来实现量子光学门，因为物质相互作用可以进化出纠缠态。因此，一项重要的任务是展示将光子纠缠映射到微腔中的物质的能力。在外加电场的作用下，纠缠的双极化子态可以独立控制光子和物质分量。通过这种外部控制，对通用的两量子位量子门进行了测试。二维金属卤化物杂化钙钛矿由于具有高的振子强度、高的激子结合能和强的多激子相互作用而被选为活性材料。法布里-珀罗微腔基于多种无机-有机杂化材料的组合，可通过组成和沉积后程序轻松调整折射率，以及可通过溶胶凝胶法沉积的金属氧化物。这个渴望的项目的成功结果需要展示一个通用的量子门，它为在量子计算中实现它奠定了平台。除了展示通用量子门的主要成果外，这项努力还需要在可寻址微腔方面的创新，从而促进可扩展室温量子光电子学材料处理协议的知识。这一奖项反映了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。

Quantum computing offers a tremendous advantage over traditional computing because it exploits quantum mechanical phenomena that can in principle carry out logic tasks much faster and more efficiently than even the best computers at present. Nevertheless, quantum computing is still in its infancy. Quantum computation exploits entanglement - a key peculiarity of quantum particles - where it is fundamentally impossible to distinguish between the properties of two identical particles, regardless of how far they are from each other. Achieving robust entanglement at room temperature remains one of the most important challenges in realizing a quantum computer. The present project overcomes existing fundamental limitations to room-temperature entanglement by designing and fabricating optical devices that produce entangled particles that are hybrids of light and matter, termed polaritons. Entangled polaritons are manipulated and controlled by applying an electrical voltage to the device. Polariton entanglement is designed to be stable over sufficiently long time to perform quantum computing operations at room temperature. In addition to the scientific and technical innovations involved in this research, it serves as a training platform to contribute to the intellectual capital and scientific infrastructure of the US, in which quantum technologies is growing in significance. Technical description: The key objective of this project is to demonstrate a universal quantum gate operating at room temperature, harnessing polariton entanglement in semiconductor microcavities that are designed to be addressable by an external electric field. Exciton polaritons are half-light, half-matter quasiparticles that are produced by strong (non-perturbative) coupling of photons and excitons. Because of their hybrid identity, exciton polaritons promise opportunities for quantum-optical gates by manipulation of entanglement in matter, since matter interactions can evolve the entangled state. An important task is thus to demonstrate the ability to map photon entanglement onto matter in microcavities. The entangled bi-polariton state can be manipulated by an applied electric field to independently control both photon and matter components. By this external control, universal two-qubit quantum gates are tested. Two-dimensional metal-halide hybrid perovskites are chosen as the active material because of their high oscillator strength, high exciton binding energy, and strong multi-exciton interactions. Fabry-Perot microcavities are based on a combination of versatile inorganic-organic hybrid materials that are readily index-tunable via composition and post-deposition procedures, and metal oxides that can be deposited by sol-gel methods. The successful outcome of this EAGER project entails a demonstration of a universal quantum gate, which lays the platform to pursue its implementation in quantum computation. Beyond the primary outcome of demonstrating a universal quantum gate, this endeavor requires innovation in addressable microcavities and thus advances knowledge of materials processing protocols for scalable room-temperature quantum optoelectronics.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.