Four Essential Principles of Quantum Computation The answer to the question “what is a quantum computer?” encompasses quantum mechanics (QM), quantum information theory (QIT) and computer science (CS). It is a device that leverages specific properties described by quantum mechanics to perform computation. We are entering a new era of computation that will catalyze discoveries in science and technology. Novel computing platforms will probe the fundamental laws of our universe and aid in solving hard problems that affect all of us. In this post I briefly outline four essential principles of quantum mechanical systems: superposition, the Born rule, entanglement, and reversible computation.