461 research outputs found
Orbital angular momentum states enabling fiber-based high-dimensional quantum communication
Quantum networks are the ultimate target in quantum communication, where many
connected users can share information carried by quantum systems. The keystones
of such structures are the reliable generation, transmission and manipulation
of quantum states. Two-dimensional quantum states, qubits, are steadily adopted
as information units. However, high-dimensional quantum states, qudits,
constitute a richer resource for future quantum networks, exceeding the
limitations imposed by the ubiquitous qubits. The generation and manipulation
of such -level systems have been improved over the last ten years, but their
reliable transmission between remote locations remains the main challenge.
Here, we show how a recent air-core fiber supporting orbital angular momentum
(OAM) modes can be exploited to faithfully transmit -dimensional states.
Four OAM quantum states and their superpositions are created, propagated in a
1.2 km long fiber and detected with high fidelities. In addition, three quantum
key distribution (QKD) protocols are implemented as concrete applications to
assert the practicality of our results. This experiment enhances the
distribution of high-dimensional quantum states, attesting the orbital angular
momentum as vessel for the future quantum network
A high-speed multi-protocol quantum key distribution transmitter based on a dual-drive modulator
We propose a novel source based on a dual-drive modulator that is adaptable
and allows Alice to choose between various practical quantum key distribution
(QKD) protocols depending on what receiver she is communicating with.
Experimental results show that the proposed transmitter is suitable for
implementation of the Bennett and Brassard 1984 (BB84), coherent one-way (COW)
and differential phase shift (DPS) protocols with stable and low quantum bit
error rate. This could become a useful component in network QKD, where
multi-protocol capability is highly desirable.Comment: 15 pages, 7 figure
Quantum cryptography: key distribution and beyond
Uniquely among the sciences, quantum cryptography has driven both
foundational research as well as practical real-life applications. We review
the progress of quantum cryptography in the last decade, covering quantum key
distribution and other applications.Comment: It's a review on quantum cryptography and it is not restricted to QK
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