Exploring tomorrow's information storage systems today.

CMRR was established at UC San Diego in 1983 to advance the state-of-the-art in information storage technology and to produce highly trained graduate students and postdoctoral professionals for the data storage industry. Pursuing a dynamic, interdisciplinary program of cutting-edge research defined in cooperation with government agencies and industry partners, the Center's faculty, researchers, and students continue to push the frontiers of scientific knowledge and engineering technology to meet society's ever-increasing need for high-performance, reliable, and secure information storage systems.


Professor Emina Soljanin

November 14, 2022

Lecture 2 PM & Reception 3 PM at JKW Auditorium


"On Some Quantom Internet Information Rates"


This talk discusses information rates in two quantum internet building blocks concerning quantum (conference) key distribution (QKD). We first focus on QKD based on time-entangled photon pairs. These systems extract key bits from photon arrival times and thus promise to deliver more than one bit per photon as opposed to polarization-entanglement QKD, where each entangled photon pair contributes at most one bit to the secret key. However, realistic photon detectors exhibit time jitter and require non-zero time to recover upon registering a photon arrival. We model and evaluate the effect of these impairments on information rates generated based on photon arrival times and ask whether time-entanglement-based QKD can live up to its promise. We next ask whether quantum network multicast can make conference key agreements more efficient. Since there is no quantum information without
physical representation (e.g., by photons), the problem of quantum multicast at first seems nothing more than the multi-commodity flow problem of shipping a collection of different commodities through a shared network. However, we show that besides the apparent similarity to the multicommodity flow problems, quantum networks, to a certain extent, behave as classical information networks. In particular, we show that lossless compression of multicast quantum states is possible and significantly reduces the link capacity requirements of the multicast.