Cryptography Apocalypse

2Introduction to Quantum Computers

Quantum computers, devices, and software use the peculiar properties of quantum mechanics discussed in Chapter 1 to manipulate, create, and process data. All those strange and wondrous quantum properties, such as superposition and spooky entanglement, are on full display in quantum information science. Chapter 2 will cover quantum computers, including how they vary from traditional computers, the different types of quantum computer architectures, and many of the companies that manufacture them.

How Are Quantum Computers Different?

This section will discuss how quantum computers differ from traditional binary classical computers. It will begin by exploring the primary difference between bits and qubits.

Traditional Computers Use Bits

Traditional computers use binary digits (0s or 1s) to store, transfer, and manipulate data. A bit (binary digit) can possibly be only one of two states: it is either a one or a zero. It is either on or off. And it can only ever be one thing (i.e., state) at one time. The underlying binary nature occurs because the manipulated particles (e.g., usually electrons, but they can be photons and other particles) are being manipulated as whole particles. Since the beginning of digital computers up until the invention of quantum computers, it was the only way we could manipulate digital information. Quantum computers allow us to manipulate particles in a nonbinary way, using their quantum properties.

Traditional computer ...