Vagniluca, Ilaria (2021) High-dimensional protocols for practical quantum key distribution over metropolitan fiber links. [Tesi di dottorato]

Anteprima

Testo vagniluca_ilaria_34.pdf Download (6MB) | Anteprima

Abstract

Quantum key distribution (QKD) enables the establishment of private keys between remote users, by exploiting a quantum technology rather than the conventional key distribution protocols. Starting from its first formulation in the 1980s, the research field behind QKD has undergone considerable development through the last decades, making it the most advanced among the other emerging quantum technologies, both at the theoretical level as well as in terms of practical implementations. However, nowadays QKD technologies and services are still rarely adopted outside the laboratories, mainly due to the high costs of implementation and to the demanding requirements in terms of environmental noise and stability of the experimental apparatus. During my PhD program, my research activity has been focused on metropolitan-scale QKD, based on fiber optic links. In particular, we have been able to implement in-field tests of QKD over an installed single-mode fiber in the metropolitan area of Florence, where we also addressed the issue of compatibility between the current QKD technologies and classical optical communication, by testing the coexistence of quantum and classical signals multiplexed in the same fiber. In the meanwhile, in the laboratory, we designed and tested novel protocols and setups for practical high-dimensional QKD. Specifically, we successfully demonstrated an efficient scheme for high-dimensional time-encoded QKD, requiring a very simplified setup, and an improved round-robin protocol with high-dimensional encoding, exhibiting higher tolerance for the noise that typically affects the quantum measurements.

Downloads

Actions (login required)

Modifica documento