Fundamentals of Quantum Communications
Savo G. Glisic, Beatriz Lorenzo · 2022
Similar to the bit, the fundamental concept of classical computation and classical information, quantum computation and quantum information are built upon an analogous concept, the quantum bit, often referred to as qubit. This chapter introduces the properties of single and multiple qubits, comparing and contrasting their properties to those of classical bits. The state of a quantum register may be changed by applying unitary operators or gates to its qubits. Quantum teleportation is a technique for moving quantum states around even in the absence of a quantum communications channel linking the sender of the quantum state to the recipient. The chapter explains how quantum parallelism works, and some of its limitations. It also introduces the concept of the Quantum Fourier Transform in a rather informal way with the goal of attracting the attention of the reader to the problem.