4 research outputs found
Entanglement verification for quantum key distribution systems with an underlying bipartite qubit-mode structure
We consider entanglement detection for quantum key distribution systems that
use two signal states and continuous variable measurements. This problem can be
formulated as a separability problem in a qubit-mode system. To verify
entanglement, we introduce an object that combines the covariance matrix of the
mode with the density matrix of the qubit. We derive necessary separability
criteria for this scenario. These criteria can be readily evaluated using
semidefinite programming and we apply them to the specific quantum key
distribution protocol.Comment: 6 pages, 2 figures, v2: final versio
Security of Binary Modulated Continuous Variable Quantum Key Distribution under Collective Attacks
We give an achievable secret key rate of a binary modulated continuous
variable quantum key distribution schemes in the collective attack scenario
considering quantum channels that impose arbitrary noise on the exchanged
signals. Bob performs homodyne measurements on the received states and the two
honest parties employ a reverse reconciliation procedure in the classical
post-processing step of the protocol.Comment: 16 pages, 2 figure