NSF-BSF: Transformation, modulation, and coupling of polariton and exciton quantum fluids

这个合作项目汇集了一个国际团队，研究被困在宏观尺度半导体结构中的光如何与电子相互作用。这些相互作用导致了非常有趣的现象，可以用来制造具有非凡功能的量子器件。这种相互作用将通过将光信号引导到保持在极低温度下的半导体微尺度结构上，并在其上施加超短电压脉冲来产生。从该项目中获得的知识为构建复杂电路、开关和其他新型量子光子技术提供了传输、存储和使用这些外来信号的新方法。该研究项目还将研究生、本科生和高中生培养成科学和工业领域的下一代领导者。它包括对K-12的推广活动，并在这项多学科研究工作中招募代表性不足的学生。摘要激子-极化子是一种人造的准粒子，以光和电子的量子叠加形式存在于半导体结构中。众所周知，它们的行为就像一种由人造原子组成的超轻气体，结合了轻粒子和大粒子的特性。研究表明，在低温下，这些准粒子会凝聚成一种集体量子基态，即玻色-爱因斯坦凝聚态。本课题将开发新的方法将相干极化子量子流体转化为偶极激子流体。这些偶极激子是半导体中寿命长且相互作用强的类原子粒子，具有丰富的多体物理现象，这些现象刚刚开始被理解。在两种非常不同类型的量子流体之间进行转换的能力，一种是与光强混合且弱相互作用，另一种更像物质且强相互作用，将允许整合每种流体的不同互补特征，并将开辟广泛的新方法来操纵半导体中物质和光的量子流体。调制集体基态的能力可以对量子流体的复杂物理学产生新的见解。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。

Nontechnical Abstract This collaborative project brings together an international team and studies how light interacts with electrons when trapped in macroscopic-scale semiconductor structures. These interactions lead to very intriguing phenomena which can be exploited for making quantum devices with remarkable functionalities. The interactions will be created by directing light signals onto semiconductor microscale structures kept at very low temperatures and on which ultra-short voltage pulses are applied. Knowledge gained from this project provides new ways of transporting, storing, and using these exotic signals for building complex circuits, switches, and other novel quantum photonic technologies. The research project also trains graduate, undergraduate and high-school students to be the next generation of leaders in science and industry. It includes outreach activities for K-12 and recruits underrepresented students in this multi-disciplinary research effort.Technical AbstractExciton-polaritons are artificial quasi-particles in the form of a quantum super-position of light and of electrons, trapped in semiconductor structures. They are known to behave like an ultra-lightweight gas of artificial atoms, combining the properties of both light and massive particles. It was shown that at low temperatures these quasi-particles condense to a collective quantum ground state known as a Bose-Einstein condensate. In this project, new methods will be developed to transform the coherent polariton quantum fluid into a fluid of dipolar exciton. These dipolar excitons are long-lived and strongly interacting atom-like particles in a semiconductor, featuring rich many-body physics phenomena that have just begun to be understood. The ability to perform transformations between two very different types of quantum fluids, one which is strongly admixed with light and weakly interacting, and one which is much more matter-like and strongly interacting, will allow integrating the different, complementary features of each of the fluids, and will open up a wide range of new ways to manipulate quantum fluids of matter and of light in semiconductors. The ability to modulate the collective ground states can lead to new insights on the complex physics of quantum fluids.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.