Development from fundamental quantum mechanics
The history of quantum information theory began at the turn of the 20th century when classical physics was revolutionized into quantum physics. … 展开

Quantum information differs strongly from classical information, epitomized by the bit, in many striking and unfamiliar ways. While the fundamental unit of classical information is the bit, the most basic unit of quantum information is the qubit. Classical information is … 展开

Entropy measures the uncertainty in the state of a physical system. Entropy can be studied from the point of view of both the classical and quantum information theories.
Classical information theory
Classical information is … 展开

Many journals publish research in quantum information science, although only a few are dedicated to this area. Among these are:
• International Journal of Quantum Information
• npj … 展开

The state of a qubit contains all of its information. This state is frequently expressed as a vector on the Bloch sphere. This state can be … 展开

Quantum mechanics is the study of how microscopic physical systems change dynamically in nature. In the field of quantum information theory, the quantum systems studied are abstracted away from any real world counterpart. A qubit might for instance physically be a 展开

Quantum communication
Quantum communication is one of the applications of quantum physics and quantum information. … 展开