Quantum Optics and Quantum Information

• Mathematical Underpinnings Of Quantum Information Theory
• Quantum Reference Frames And Resource Theory Of Asymmetry
• Quantum Information and Measurement

Quantum Optics: It's a field of research that deals with the application of quantum mechanics to phenomena involving light and its interactions with matter. One of the main goals is to understand the quantum nature of information and to learn how to formulate, manipulate, and process it using physical systems that operate on quantum mechanical principles.

Quantum Communication: Quantum communication is a field of applied quantum physics closely associated with quantum information science and quantum teleportation. Its most interesting application is protecting information channels against eavesdropping by means of quantum cryptography. The most distinguished and developed application of quantum cryptography is a quantum key distribution (QKD). QKD describes the utilization of quantum mechanical effects to perform cryptographic responsibilities or to interrupt cryptographic systems.

Methods for encoding and decoding the photons:

Polarization: the binary information "1" or "0" is defined by the polarization of the only photons, e.g., binary "0" correlates with the horizontally polarized photon and binary "1" with vertically polarized photon

Phase: The which involves the use of an interferometer system: the phase difference Δφ = φAlice - φBob of the two interferometers is then used for encoding the binary values, e.g., a phase difference Δφ=0 correlates with the binary "0" and the phase difference Δφ=π correlates with the binary "1"

Entangled photons: which desires one sender of entangled photon pairs and two receivers (Alice and Bob) each equipped with a polarizer. Alice and Bob set the two angles at their respective polarization rotator randomly. If the angles of Alice and Bob match, both photons behave precisely the same at the beam splitter, i.e., they're either transmitted (binary "1") or reflected (binary "0").