QuIC ‐ TAQS: A Photon‐Phonon Quantum Interconnect via Brillouin‐Based Optomechanics in Quartz and Superfluid

Yale University, New Haven CT

Investigators

Abstract

Quantum particles of light (photons) are used to transmit quantum information over long distances within an optical quantum network. However, increased versatility and performance of these networks also requires the ability to store and retrieve quantum information in local devices. Quantized particles of sound (phonons) are promising candidates for the storage of quantum information but achieving efficient photon-phonon conversion and long storage times remains challenging. This program addresses these challenges by creating new chip-based technologies that combine the world’s best photonic cavities with new phononic resonators fashioned from ultra-high purity crystals and quantum fluids. Using resonantly enhanced material couplings to access long-lived phonons within crystalline and superfluid resonators, a new approach for an efficient and scalable quantum interconnect becomes possible. Using a hybrid integration strategy that builds on wafer-scale photonic integrated circuit technologies, this work paves the way for scalable quantum memories, quantum sensors, and quantum repeaters. The educational and outreach activities of this project also provide special research opportunities for community college transfer students, undergraduate research, and international collaborations. Photons are used to transmit quantum information over long distances within quantum networks. However, increased versatility and performance of these networks also requires the ability to store and retrieve quantum information from long-lived local quantum excitations. Phonons are promising candidates for such local excitations but achieving an efficient photon-phonon interconnect is challenging. This research program meets this challenge by combining the world’s best on-chip optical cavities with new phononic resonators fashioned from ultra-high purity crystalline quartz and superfluid helium. Efficient access to the long-lived phonon modes within these media is created by tailoring the device geometry to create strong Brillouin coupling. Through Brillouin processes, an incident photon scatters to a phonon and a red-shifted photon; these scattered particles form a quantum-entangled pair. By combining and detecting scattered photons produced by two such systems, phonons stored in cavities at remote locations become entangled. Combining rapid photon-phonon conversion and long coherence times, many quantum operations can be performed within the phonon lifetime making more complex operations possible. Employing a hybrid integration approach that leverages the benefits of wafer-scale photonic integrated circuit technologies, these new quantum devices pave the way for scalable quantum memories, quantum sensors, and quantum repeaters. 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.