Category: Quantum Information Technology

  • Quantum Teleportation

    Star Trek introduced us to the fantastic notion of teleporting humans from one place to another, such as from the Starship Enterprise to planets beneath. Doing so was quite convenient, and eliminated the need for expensive landings and takeoffs. It certainly would make life more convenient if we could avoid the morning commute and just teleport…

  • Quantum Cryptography

    Sharing secrets is as old as humanity, and evidence of coded messages has been traced back to ancient civilizations. Cryptography is a technique intended to code a message into an incomprehensible string of characters that can only be decoded by the intended recipient. And, just as the lock on your front door can only be…

  • Building a Quantum Computer

    While this all sounds great in theory, building a useful quantum computer turns out to be pretty tricky. There are two challenges in particular that will need to be overcome before qubits are actually applied on our desktops or in our mobile phones. When performing our operations, we introduce well-characterized perturbations to the qubits, which…

  • Quantum Computation

    Now that we understand how to set up a quantum computer, at least in theory, how can it be used to perform actual calculations? Just like in the classical case, the process boils down to three steps. First, our set of qubits must be prepared, or initialized, into a starting state. Then, we would have…

  • Bits vs. Qubits

    The basic unit of information in a classical computer is a bit, which is a little register that can take on two possible values usually called “0” and “1.” If one bit can take two values (0 and 1), then two bits can take four (22) values (00, 01, 10, and 11). Three bits offers…

  • The Quantum Computer

    Computers are used practically everywhere and in just about everything. In the 1960s the first computers could fill a small room. Today, computers are small enough to fit in the palms of our hands, or even smaller, thanks to improved semiconductor technologies. Manufacturers are now capable of making nanometer-sized (10-9 meter) computer chips, or nanochips. The…

  • Introduction

    We have learned throughout this book that discoveries in quantum physics have allowed us to better understand nature. Though it provides many answers, it also continues to open up even deeper puzzles. To address these, scientists keep expanding and improving their theories and experiments, and have occasionally stumbled upon major discoveries so unexpected that they…