Quantum Cryptography: Optical Qubits and Teleportation

This lecture covers the principles of quantum cryptography, focusing on optical qubits and their applications. It begins with a review of entangled states and their significance in quantum communication. The instructor explains how quantum key distribution (QKD) works, emphasizing the importance of maintaining the integrity of the quantum channel against eavesdropping. The discussion includes Bell's measurements and the implications of losing entanglement. The lecture then transitions to the concept of quantum teleportation, illustrating it through analogies and mathematical details. The instructor highlights the necessity of not measuring certain parameters to preserve quantum states during teleportation. The lecture concludes with a discussion on the limitations of quantum cloning and the potential for future advancements in quantum computing and cryptography, including practical applications in secure communication systems. Overall, the lecture provides a comprehensive overview of the theoretical and practical aspects of quantum cryptography and teleportation.