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

量子计算比传统计算具有巨大的优势，因为它利用量子力学现象，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。尽管如此，量子计算仍处于起步阶段。量子计算利用了纠缠——量子粒子的一个关键特性——基本上不可能区分两个相同粒子的属性，无论它们彼此相距多远。在室温下实现稳健的纠缠仍然是实现量子计算机的最重要挑战之一。本项目通过设计和制造产生纠缠粒子的光学器件，克服了室温纠缠的现有基本限制，这些粒子是光和物质的混合体，称为极化激元。通过向设备施加电压来操纵和控制纠缠极化子。极化子纠缠被设计为在足够长的时间内保持稳定，以便在室温下执行量子计算操作。除了这项研究涉及的科学和技术创新之外，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，其中量子技术的重要性日益增强。 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子纠缠，这些半导体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。由于其混合特性，激子极化激元通过操纵物质中的纠缠为量子光门提供了机会，因为物质相互作用可以演化纠缠态。因此，一项重要的任务是证明将光子纠缠映射到微腔物质上的能力。纠缠双极化子态可以通过施加的电场来操纵，以独立控制光子和物质成分。通过这种外部控制，测试了通用的二量子位量子门。二维金属卤化物杂化钙钛矿因其高振荡强度、高激子结合能和强多激子相互作用而被选为活性材料。法布里-珀罗微腔基于多功能无机-有机杂化材料和金属氧化物的组合，这些材料可以通过成分和后沉积程序轻松调节折射率，并且可以通过溶胶-凝胶方法沉积金属氧化物。这个 EAGER 项目的成功成果需要展示通用量子门，这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之外，这项努力还需要在可寻址微腔方面进行创新，从而提高可扩展室温量子光电子学材料加工协议的知识。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力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 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.