Quantum Computation and Quantum Information: 10th Anniversary Edition by Michael A. Nielsen et al. (Kindle Edition)

Good discount on an excellent textbook. Existing computers work with deterministic, classical bits in a single known state, but quantum computers work with qubits in a superposition of states so that operations, operators, and computations can be carried out on a huge number of states simultaneously.

"This comprehensive textbook describes such remarkable effects as fast quantum algorithms, quantum teleportation, quantum cryptography and quantum error-correction. Quantum mechanics and computer science are introduced before moving on to describe what a quantum computer is, how it can be used to solve problems faster than 'classical' computers and its real-world implementation. It concludes with an in-depth treatment of quantum information."