Entangled Photons and Entanglement Witnesses
Note (1/28/24): This project is being posted for summer 2024 but is contingent on funding and logistics of my summer travel.
In this project, we will study verification of quantum entanglement in partially entangled pairs, a capability essential for the smooth operation of a future “quantum internet.” Entangled pairs are necessary for numerous secure communication protocols, in which the equipment needed to carry out the protocols is much simpler than the equipment needed to produce the entangled particles. Individual users will be able to perform quantum communication and cryptography using entangled pairs provided by a third party. In this setting, it is important to identify reliable and efficient measurements the users can perform to test that they are truly receiving entangled pairs. Such measurements are called entanglement witnesses. The best-known entanglement witnesses require a large number of different measurements by users, and are only sensitive to entanglement that is near-perfect in quality. Our group has studied witnesses proposed in the literature to overcome one or both of these issues, and has proposed new adaptive-measurement strategies to maximize the chance of witnessing entanglement with a limited number of measurements. In summer 2024 we plan to expand our entangled-photon apparatus to create and measure a wider range of entangled states; we can then demonstrate various aspects of our group's proposed adaptive witnessing protocol.
For students with appropriate interest and background, there is also a possibility of working on further theoretical aspects of the protocol itself.
Please write a short essay response to this question: What interests you most about working on this project and in this research group? How does this project align with your existing skills and experience, and/or with your future goals?
Research in the Lynn Lab explores aspects of quantum entanglement. Entangled pairs of particles exhibit correlated properties that cannot be understood via classical reasoning. Though the concept of entanglement is nearly 100 years old, currently entanglement is in the spotlight as an essential resource for quantum computing and communication. Some fundamental aspects remain poorly understood, particularly for partially entangled pairs of particles and entangled particles whose internal structure is more complicated than the canonical 'quantum bit.' Our work this summer tackles aspects of entanglement with experimental and theoretical tools.
Along with research on the experimental project itself, Lynn Lab members are encouraged to participate in a journal club with other summer researchers in the physics department, and to take part in social and extracurricular opportunities in the department and college's summer research community.