CAREER: Photonic Quantum Technologies with Strain-Free Artificial Atoms

Quantum technologies promise unbreakable security based on the laws of physics and offer powerful new tools to simulate problems that are currently beyond the reach of classical computers. However, realizing these breakthroughs requires new resources that are not yet readily available. Among various quantum systems, photons —particles of light— stand out as ideal carriers for communication and sensing applications. A key challenge today is the lack of deterministic, high-quality sources of photons suitable for scalable quantum technologies. This project aims to address that challenge by developing large entangled states of photons using a new class of artificial atoms suited for scalability and integration. In addition to advancing the scientific frontier, the project includes initiatives to attract and train undergraduate students in quantum science and engineering—helping build the future quantum workforce. Furthermore, dedicated efforts will be made to effectively communicate and disseminate knowledge about quantum technologies to the broader public, fostering wider understanding and engagement. Technical Description: The prerequisite for exploiting photons in larger-scale problems is producing high-quality streams of entangled photons. The standard method for generating these states is probabilistic, with a low success rate of around 3%, and suffers from large overheads when scaling to large photon numbers. Quantum emitters have been proposed as an alternative for generating quantum states deterministically. Additionally, multiple quantum emitters can be entangled together to generate complex quantum resources, such as quantum entanglement between many photons. Yet, the progress on this front has been slow primarily due to shortcomings in material properties and noise in the environment of the quantum emitters. This project addresses the scalable generation of quantum photonic resources by employing a new class of artificial atoms named gallium arsenide quantum dots (GaAs QDs). Contrary to standard QDs, GaAs QDs are free from strain, it has recently been shown that GaAs QDs possess low-noise ground states (long spin coherence time), and that different GaAs QDs have identical optical properties. These are critical requirements for interfacing multiple quantum emitters in a scalable platform. In this project, we will realize a scalable platform where several artificial atoms are interfaced on a photonic chip, providing extensive quantum resources. Each QD can generate many photons, and multiple emitters can be entangled to generate complex entanglement geometries. The project integrates education and outreach by developing a new undergraduate course on quantum technologies, aimed at preparing students for advanced studies in this emerging field. It also includes outreach efforts such as high school modules and public seminars to broaden access to quantum science. 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.