What Does a Quantum Physicist Do?

Quantum is an important concept in modern physics. That is, if a physical quantity has the smallest indivisible basic unit, the physical quantity is quantized, and the smallest unit is called a quantum.

If a physical quantity has the smallest indivisible

The basic idea of quantum communication was mainly proposed by Bennett in the 1980s and 1990s. It mainly includes quantum key distribution (QKD) and quantum teleportation. Quantum key distribution can establish secure communication passwords, and one-on-one encryption can be used to achieve secure classic communication in a point-to-point manner. The security here is the security that has been mathematically rigorously proven, which is what classic communication has done so far No. The existing quantum key distribution technology can achieve quantum key distribution on the order of hundreds of kilometers, supplemented by technologies such as optical switches, and can also implement quantum key distribution networks. Quantum state teleportation is based on the distribution of quantum entangled states and the joint measurement of quantum.It realizes the spatial transfer of quantum states (quantum information) without moving the quantum state. It is like transferring the content of a sealed letter from one envelope to another. The envelope does not move any information carrier itself. This is unimaginable in classic communication. Quantum repeaters based on quantum state teleportation technology and quantum storage technology can realize quantum key distribution and network at any distance.

The realization of quantum communication is based on quantum state transmission. In order to facilitate transmission, the existing quantum communication experiments generally use photons as the carrier of the quantum state, and its expression is photon state transmission. The coding space of quantum information is mainly based on the polarization of light. ^[3]