Randomness in Quantum Computation

Introducing randomness by computationally flipping a coin can increase the efficiency of classical computer algorithms. Quantum computing may also benefit from the introduction of randomness, but doing so is less straightforward because at any step, a quantum computer can follow a continuous set of possible paths. In his Perspective, [Paz][1] explains that a good approximation of randomness can be introduced more easily than was anticipated. He highlights the report by [ Emerson et al .][2], who have devised a two-step procedure that allows the efficient implementation of quantum coin-tosses in an approximate but useful way. [1]: http://www.sciencemag.org/cgi/content/full/302/5653/2076 [2]: http://www.sciencemag.org/cgi/content/short/302/5653/2098