Quantum Cryptography and the Roles Played by Optics

Martin Kristensen

Konstantin Kravtsov, I. V. Radchenko, A. V. Korol’kov +2 more

The stability of destructive interference independent of the input polarization and the state of a quantum communication channel in fiber optic systems used in quantum cryptography plays a principal role in providing the security of communicated keys. A novel optical scheme is proposed that can be used both in relativistic quantum cryptography for communicating keys in open space and for communicating them over fiber optic lines. The scheme ensures stability of destructive interference and admits simple automatic balancing of a fiber interferometer.

Madison Durrance, Zach Galberd, Abbey Savage +2 more

Wenqin Chen

Quantum cryptography exploits the quantum mechanical principle that observation in general disturbs the system being observed. Of particular interest is the role played by entanglement, which doesn’t yet have a complete theory. In this thesis, we attempt to classify quantum entanglement and explore how the properties of quantum entanglement allow for applications in information transmission and quantum cryptography.

Gilles Brassard A

Y. Yamamoto, Charles Santori, Glenn S. Solomon +4 more

This paper reviews the current state of single-photon sources based on the semiconductor quantum dots that will play a central role in future quantum information systems.By optically pumping a system consisting of a semiconductor single quantum dot confined in a monolithic microcavity, it is possible to produce a single-photon pulse stream at the Fourier transform limit with high efficiency and a high repetition rate.This technique is not only useful for BB84 quantum cryptography using single photons, but will also find applications in other quantum information systems such as BBM92 quantum cryptography using entangled photon pairs, quantum teleportation, quantum repeaters, and linear optical quantum computers.