11:41 a.m.
Ciao a tutti,
Tomorrow, 3 May, at 14:30 in D5.01 we are happy to welcome Giacomo Carrara from
Heinrich-Heine-Universität Düsseldorf to the CQI seminar as a guest speaker. Giacomo will
talk about his work on twin-field quantum key distribution, title and abstract below.
As always you can join us online at https://meet.jit.si/cqi-demon-M6QW9V7YY.
Looking forward to seeing you there,
Will
Speaker: Giacomo Carrara
Title: Overcoming fundamental bounds on quantum conference key agreement
Abstract: Twin-Field Quantum Key Distribution (TF-QKD) enables two distant parties to
establish a shared secret key, by interfering weak coherent pulses (WCPs) in an
intermediate measuring station. This allows TF-QKD to reach greater distances than
traditional QKD schemes and makes it the only scheme capable of beating the repeaterless
bound on the bipartite private capacity. Here, we generalize TF-QKD to the multipartite
scenario. Specifically, we propose a practical conference key agreement (CKA) protocol
that only uses WCPs and linear optics and prove its security with a multiparty decoy-state
method. Our protocol allows an arbitrary number of parties to establish a secret
conference key by single-photon interference, enabling it to overcome recent bounds on the
rate at which conference keys can be established in quantum networks without a repeater.