Entangled photons for Attosecond Science - College of Engineering - Purdue University

Entangled photon pairs are a vital resource for quantum information, computation, and metrology. Although these states are routinely generated at optical frequencies, sources of quantum of light are notably lacking at extreme ultraviolet frequencies and with ultrabroadband – associated with attosecond resolution. In this collaborative project between the groups of PI Niranjan Shivaram (Purdue) and PI Oren Cohen (Technion), entangled photons will be generated and studied for use in attosecond quantum spectroscopy using two approaches. In one approach, ultrabroadband attosecond entangled photons (biphotons) will be generated from two-photon decay of femtosecond laser excited metastable helium atoms [Phys. Rev. Research 4, L032038 (2022)]. The candidate is expected to lead efforts in measuring entanglement of these biphotons by performing attosecond photoionization experiments to gain new insight into attosecond electron dynamics. In another approach, generation of entangled photons through high harmonic generation will be explored [https://arxiv.org/pdf/2309.16466].