CAREER: Quantum Control of Trapped Ion Qubits with Electro-Optic Integrated Photonic Circuits

Precise control of laser light is critical for many areas of science, including quantum computing with atoms and ions. Quantum computers could solve outstanding problems in material science, chemistry, and physics. However, in order to build useful quantum computers the research community needs several tools such as improved photonics devices that can be integrated into quantum computer prototypes. Some modern photonics devices for controlling laser light are already fabricated in the same facilities that are used to make silicon computer chips, leveraging nanometer-sized features on small silicon chips to control the propagation of light. Advances in this approach can lead to high performance devices in compact packages that could replace current bulky and fragile optics systems used for quantum computer prototypes today. One of the challenges is that quantum computing operations with atoms require both high power and precise laser frequency control. This project will evaluate the use of state-of-the-art photonic technologies for quantum computing with trapped ions. When successful, the integration of photonic devices could expand current quantum computers from 100 to 1000 qubits and enable transformative advances in science and engineering. This project involves students at all levels – from K-12 summer programs to community college internships. The research emphasizes interdisciplinary engineering, and the student involvement will expand quantum education and promote the field to the next generation of scientists and engineers. Thin-film lithium niobate (TFLN) offers high electro-optic nonlinearity and tight optical confinement, making it a strong candidate for miniaturized photonic components such as those needed for trapped ion quantum computing. However, its behavior under visible light — especially the photorefractive (PR) instabilities that can distort control signals — remains poorly understood and is a core focus of this research. This CAREER project explores the integration of TFLN photonic devices into quantum systems to enable compact, fast, and precise control of laser light. The three main research goals are: (1) understanding PR in TFLN, (2) assessing its impact on ion-based quantum control, and (3) building the first trap-integrated TFLN modulator. The research goals address a critical challenge in scaling trapped-ion quantum computers by integrating optical modulators directly into surface electrode ion traps using TFLN, an emerging and highly promising photonic platform. This approach leverages the ability to fabricate trap electrodes directly atop lithium niobate modulators, offering a compact and potentially scalable solution. 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.